diff --git a/app/controllers/accounts_controller.rb b/app/controllers/accounts_controller.rb
new file mode 100644
index 0000000..67f43be
--- /dev/null
+++ b/app/controllers/accounts_controller.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class AccountsController < ApplicationController
+  before_action :set_account, only: %i[show]
+
+  def show
+    render json: @account, serializer: AccountProfileSerializer, scope: current_user
+  end
+
+  private
+
+  def set_account
+    @account = User.includes(:tournaments, player_teams: :tournament).find(params[:id])
+  end
+end
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 97043de..a3451c5 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -9,6 +9,7 @@ class ApplicationController < ActionController::API
   rescue_from ActionController::ParameterMissing do |e|
     render json: { error: e.message }, status: :bad_request
   end
+  rescue_from ActiveRecord::RecordInvalid, with: :render_record_invalid_error
   rescue_from ActiveRecord::RecordNotFound, with: :render_not_found_error
 
   protected
@@ -56,7 +57,7 @@ class ApplicationController < ActionController::API
   end
 
   def require_writable_tournament!(tournament)
-    render_read_only_error if tournament.read_only_mode?
+    render_read_only_error if tournament&.read_only_mode?
   end
 
   def render_not_found_error(exception)
@@ -67,4 +68,8 @@ class ApplicationController < ActionController::API
             end
     render json: { error: error }, status: :not_found
   end
+
+  def render_record_invalid_error(exception)
+    render json: exception.record.errors, status: :unprocessable_content
+  end
 end
diff --git a/app/controllers/teams_controller.rb b/app/controllers/teams_controller.rb
index d6e07c4..0450240 100644
--- a/app/controllers/teams_controller.rb
+++ b/app/controllers/teams_controller.rb
@@ -3,7 +3,7 @@
 class TeamsController < ApplicationController
   before_action :set_team, only: %i[show update]
   before_action :authenticate_user!, only: %i[update]
-  before_action -> { require_owner! @team.owner }, only: %i[update]
+  before_action :require_team_update_actor!, only: %i[update]
   before_action -> { require_writable_tournament!(@team.tournament) }, only: %i[update]
 
   # GET /teams/1
@@ -13,12 +13,19 @@ class TeamsController < ApplicationController
 
   # PATCH/PUT /teams/1
   def update
-    if @team.update(team_params)
-      push_sync_if_needed!(@team.tournament)
-      render json: @team
-    else
-      render json: @team.errors, status: :unprocessable_content
+    Team.transaction do
+      @team.assign_attributes(team_params)
+      assign_players_from_params if player_assignment_requested?
+      raise ActiveRecord::Rollback if performed?
+
+      @team.save!
     end
+    return if performed?
+
+    push_sync_if_needed!(@team.tournament)
+    render json: @team
+  rescue ActiveRecord::RecordInvalid => e
+    render json: e.record.errors, status: :unprocessable_content
   end
 
   private
@@ -31,6 +38,83 @@ class TeamsController < ApplicationController
     params.slice(:name).permit!
   end
 
+  def player_assignment_requested?
+    params.key?(:player_email) || params.key?(:player_id) ||
+      params.key?(:player_emails) || params.key?(:player_ids)
+  end
+
+  def assign_players_from_params
+    unless tournament_owner?
+      render_forbidden_error
+      return
+    end
+
+    if params.key?(:player_emails)
+      @team.players = players_from_emails(params[:player_emails])
+    elsif params.key?(:player_ids)
+      @team.players = players_from_ids(params[:player_ids])
+    elsif params.key?(:player_email)
+      add_or_clear_player_from_email
+    else
+      add_or_clear_player_from_id
+    end
+  rescue ActiveRecord::RecordInvalid => e
+    render json: e.record.errors, status: :unprocessable_content
+  end
+
+  def players_from_emails(emails)
+    email_values(emails).map { |email| User.find_or_create_player_by_email!(email) }
+  end
+
+  def players_from_ids(player_ids)
+    id_values = Array.wrap(player_ids).map(&:to_s).map(&:strip).reject(&:blank?)
+    return [] if id_values.empty?
+
+    User.where(id: id_values).tap do |players|
+      unless players.size == id_values.uniq.size
+        raise ActiveRecord::RecordNotFound.new('Could not find all players', 'User')
+      end
+    end
+  end
+
+  def add_or_clear_player_from_email
+    email = params[:player_email].to_s.strip
+    if email.blank?
+      @team.players = []
+      return
+    end
+
+    add_player(User.find_or_create_player_by_email!(email))
+  end
+
+  def add_or_clear_player_from_id
+    player_id = params[:player_id].to_s.strip
+    if player_id.blank?
+      @team.players = []
+      return
+    end
+
+    add_player(User.find(player_id))
+  end
+
+  def add_player(player)
+    @team.players << player unless @team.player_ids.include?(player.id)
+  end
+
+  def email_values(emails)
+    Array.wrap(emails).map(&:to_s).map(&:strip).reject(&:blank?)
+  end
+
+  def require_team_update_actor!
+    return if tournament_owner? || @team.players.include?(current_user)
+
+    render_forbidden_error
+  end
+
+  def tournament_owner?
+    @team.owner == current_user
+  end
+
   def push_sync_if_needed!(tournament)
     TournamentSyncEnqueue.call(tournament)
   end
diff --git a/app/controllers/tournaments_controller.rb b/app/controllers/tournaments_controller.rb
index e2cc26c..04f92c2 100644
--- a/app/controllers/tournaments_controller.rb
+++ b/app/controllers/tournaments_controller.rb
@@ -274,7 +274,14 @@ class TournamentsController < ApplicationController
     if team[:id]
       Team.find team[:id]
     elsif team[:name]
-      Team.create name: team[:name]
+      Team.create(name: team[:name], players: players_from_team_params(team))
+    end
+  end
+
+  def players_from_team_params(team)
+    player_emails = team[:player_emails].presence || team[:player_email]
+    Array.wrap(player_emails).map(&:to_s).map(&:strip).reject(&:blank?).map do |player_email|
+      User.find_or_create_player_by_email!(player_email)
     end
   end
 
@@ -287,7 +294,7 @@ class TournamentsController < ApplicationController
     @tournament = profiling.measure('load_tournament') do
       Tournament.includes(
         :user,
-        :teams,
+        { teams: :players },
         stages: [
           { matches: { match_scores: :team } },
           { groups: [
diff --git a/app/models/team.rb b/app/models/team.rb
index 4ad8508..57c2a44 100644
--- a/app/models/team.rb
+++ b/app/models/team.rb
@@ -2,6 +2,8 @@
 
 class Team < ApplicationRecord
   belongs_to :tournament, optional: true
+  has_many :team_players, dependent: :destroy
+  has_many :players, through: :team_players
   has_many :group_scores, dependent: :destroy
   has_many :match_scores, dependent: :destroy
   has_many :bets, dependent: :destroy
@@ -9,5 +11,5 @@ class Team < ApplicationRecord
 
   validates :name, presence: true
 
-  delegate :owner, to: :tournament
+  delegate :owner, to: :tournament, allow_nil: true
 end
diff --git a/app/models/team_player.rb b/app/models/team_player.rb
new file mode 100644
index 0000000..ada0c3a
--- /dev/null
+++ b/app/models/team_player.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+class TeamPlayer < ApplicationRecord
+  belongs_to :team
+  belongs_to :player, class_name: 'User'
+end
diff --git a/app/models/user.rb b/app/models/user.rb
index 6d2a109..7e156c0 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -11,5 +11,38 @@ class User < ApplicationRecord
   validates :username, presence: true, uniqueness: { case_sensitive: false }
 
   has_many :tournaments, dependent: :destroy
+  has_many :team_players, foreign_key: :player_id, inverse_of: :player, dependent: :destroy
+  has_many :player_teams, through: :team_players, source: :team
+  has_many :played_tournaments, -> { distinct }, through: :player_teams, source: :tournament
   has_many :bets, dependent: :destroy
+
+  class << self
+    def find_or_create_player_by_email!(email)
+      normalized_email = email.to_s.strip.downcase
+      where('LOWER(email) = ?', normalized_email).first || create!(email: normalized_email) do |user|
+        generated_password = Devise.friendly_token.first(24)
+        user.username = unique_player_username(normalized_email)
+        user.password = generated_password
+        user.password_confirmation = generated_password
+        user.confirmed_at = Time.current
+        user.uid = normalized_email
+        user.provider = 'email'
+      end
+    end
+
+    private
+
+    def unique_player_username(email)
+      base = email.split('@').first.to_s.parameterize.presence || 'player'
+      candidate = base
+      suffix = 2
+
+      while where('LOWER(username) = ?', candidate.downcase).exists?
+        candidate = "#{base}-#{suffix}"
+        suffix += 1
+      end
+
+      candidate
+    end
+  end
 end
diff --git a/app/serializers/account_profile_serializer.rb b/app/serializers/account_profile_serializer.rb
new file mode 100644
index 0000000..de9a2ed
--- /dev/null
+++ b/app/serializers/account_profile_serializer.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+class AccountProfileSerializer < AccountSummarySerializer
+  attributes :tournaments, :created_tournaments, :teams
+
+  def tournaments
+    visible_played_tournaments.map { |tournament| tournament_summary(tournament) }
+  end
+
+  def created_tournaments
+    visible_created_tournaments.map { |tournament| tournament_summary(tournament) }
+  end
+
+  def teams
+    visible_player_teams.map do |team|
+      {
+        id: team.id,
+        name: team.name,
+        tournament: tournament_summary(team.tournament)
+      }
+    end
+  end
+
+  private
+
+  def visible_played_tournaments
+    visible_tournaments(object.played_tournaments.order(:created_at))
+  end
+
+  def visible_created_tournaments
+    visible_tournaments(object.tournaments.order(:created_at))
+  end
+
+  def visible_player_teams
+    object.player_teams.includes(:tournament).order(:created_at).select do |team|
+      profile_owner? || team.tournament&.public?
+    end
+  end
+
+  def visible_tournaments(scope)
+    return scope if profile_owner?
+
+    scope.where(public: true)
+  end
+
+  def profile_owner?
+    scope == object
+  end
+
+  def tournament_summary(tournament)
+    return nil if tournament.nil?
+
+    {
+      id: tournament.id,
+      name: tournament.name,
+      code: tournament.code,
+      public: tournament.public
+    }
+  end
+end
diff --git a/app/serializers/account_summary_serializer.rb b/app/serializers/account_summary_serializer.rb
new file mode 100644
index 0000000..6d2ae03
--- /dev/null
+++ b/app/serializers/account_summary_serializer.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class AccountSummarySerializer < ApplicationSerializer
+  attributes :name, :username
+
+  def name
+    object.username
+  end
+end
diff --git a/app/serializers/team_serializer.rb b/app/serializers/team_serializer.rb
index cf33a86..5799663 100644
--- a/app/serializers/team_serializer.rb
+++ b/app/serializers/team_serializer.rb
@@ -1,5 +1,9 @@
 # frozen_string_literal: true
 
 class TeamSerializer < ApplicationSerializer
-  attributes :name
+  attributes :name, :players
+
+  def players
+    object.players.map { |player| AccountSummarySerializer.new(player).as_json }
+  end
 end
diff --git a/app/serializers/tournament_serializer.rb b/app/serializers/tournament_serializer.rb
index 8777d91..f23cf83 100644
--- a/app/serializers/tournament_serializer.rb
+++ b/app/serializers/tournament_serializer.rb
@@ -34,6 +34,7 @@ class TournamentSerializer < SimpleTournamentSerializer
       {
         id: team.id,
         name: team.name,
+        players: team.players.map { |player| AccountSummarySerializer.new(player).as_json },
         advancing_from_group_stage: adv_teams.include?(team)
       }
     end
diff --git a/config/routes.rb b/config/routes.rb
index c3d4396..55886ed 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -19,6 +19,7 @@ Rails.application.routes.draw do
   end
   resources :stages, only: %i[show update]
   resources :teams, only: %i[show update]
+  resources :accounts, only: %i[show]
   resources :team_action_items, only: %i[update]
   resources :tournaments do
     resources :team_action_lists, only: %i[create]
diff --git a/db/migrate/20260504120000_create_team_players.rb b/db/migrate/20260504120000_create_team_players.rb
new file mode 100644
index 0000000..da3af52
--- /dev/null
+++ b/db/migrate/20260504120000_create_team_players.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class CreateTeamPlayers < ActiveRecord::Migration[7.0]
+  def change
+    create_table :team_players do |t|
+      t.references :team, null: false, type: :integer, foreign_key: { on_delete: :cascade }, index: true
+      t.references :player,
+                   null: false,
+                   type: :integer,
+                   foreign_key: { to_table: :users, on_delete: :cascade },
+                   index: true
+
+      t.timestamps
+    end
+
+    add_index :team_players, %i[team_id player_id], unique: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 46f5577..0d5a2ed 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.1].define(version: 2026_05_04_101000) do
+ActiveRecord::Schema[8.1].define(version: 2026_05_04_120000) do
   create_table "beamers", force: :cascade do |t|
     t.json "config", default: {}, null: false
     t.datetime "created_at", null: false
@@ -124,6 +124,16 @@ ActiveRecord::Schema[8.1].define(version: 2026_05_04_101000) do
     t.index ["tournament_id"], name: "index_team_action_lists_on_tournament_id"
   end
 
+  create_table "team_players", force: :cascade do |t|
+    t.datetime "created_at", null: false
+    t.integer "player_id", null: false
+    t.integer "team_id", null: false
+    t.datetime "updated_at", null: false
+    t.index ["player_id"], name: "index_team_players_on_player_id"
+    t.index ["team_id", "player_id"], name: "index_team_players_on_team_id_and_player_id", unique: true
+    t.index ["team_id"], name: "index_team_players_on_team_id"
+  end
+
   create_table "teams", force: :cascade do |t|
     t.datetime "created_at", precision: nil, null: false
     t.string "name"
@@ -240,6 +250,8 @@ ActiveRecord::Schema[8.1].define(version: 2026_05_04_101000) do
   add_foreign_key "team_action_items", "team_action_lists", on_delete: :cascade
   add_foreign_key "team_action_items", "teams", on_delete: :cascade
   add_foreign_key "team_action_lists", "tournaments", on_delete: :cascade
+  add_foreign_key "team_players", "teams", on_delete: :cascade
+  add_foreign_key "team_players", "users", column: "player_id", on_delete: :cascade
   add_foreign_key "teams", "tournaments", on_delete: :cascade
   add_foreign_key "tournament_sync_queue_entries", "tournaments", on_delete: :cascade
   add_foreign_key "tournament_transaction_log_entries", "tournaments", on_delete: :cascade
diff --git a/spec/controllers/accounts_controller_spec.rb b/spec/controllers/accounts_controller_spec.rb
new file mode 100644
index 0000000..95ac9b4
--- /dev/null
+++ b/spec/controllers/accounts_controller_spec.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe AccountsController, type: :controller do
+  describe 'GET #show' do
+    let(:account) { create(:user, username: 'player-one') }
+    let(:public_team) { create(:team, name: 'Public Team', players: [account]) }
+    let(:private_team) { create(:team, name: 'Private Team', players: [account]) }
+    let(:public_tournament) { create(:tournament, public: true, teams: [public_team]) }
+    let(:private_tournament) { create(:tournament, public: false, teams: [private_team]) }
+    let(:created_public_tournament) { create(:tournament, user: account, public: true) }
+    let(:created_private_tournament) { create(:tournament, user: account, public: false) }
+
+    before do
+      public_tournament
+      private_tournament
+      created_public_tournament
+      created_private_tournament
+    end
+
+    it 'returns public account profile information' do
+      get :show, params: { id: account.to_param }
+
+      body = deserialize_response(response)
+      expect(response).to be_successful
+      expect(body[:id]).to eq(account.id)
+      expect(body[:name]).to eq('player-one')
+      expect(body[:username]).to eq('player-one')
+      expect(body[:teams].map { |team| team[:id] }).to eq([public_team.id])
+      expect(body[:tournaments].map { |tournament| tournament[:id] }).to eq([public_tournament.id])
+      expect(body[:created_tournaments].map { |tournament| tournament[:id] }).to eq([created_public_tournament.id])
+    end
+
+    it 'returns private profile information to the account owner' do
+      apply_authentication_headers_for account
+
+      get :show, params: { id: account.to_param }
+
+      body = deserialize_response(response)
+      expect(body[:teams].map { |team| team[:id] }).to match_array([public_team.id, private_team.id])
+      expect(body[:tournaments].map { |tournament| tournament[:id] })
+        .to match_array([public_tournament.id, private_tournament.id])
+      expect(body[:created_tournaments].map { |tournament| tournament[:id] })
+        .to match_array([created_public_tournament.id, created_private_tournament.id])
+    end
+
+    it 'returns not found for unknown accounts' do
+      get :show, params: { id: User.maximum(:id).to_i + 1 }
+
+      expect(response).to have_http_status(:not_found)
+    end
+  end
+end
diff --git a/spec/controllers/teams_controller_spec.rb b/spec/controllers/teams_controller_spec.rb
index 8dc9eb1..bd6cc19 100644
--- a/spec/controllers/teams_controller_spec.rb
+++ b/spec/controllers/teams_controller_spec.rb
@@ -19,6 +19,17 @@ RSpec.describe TeamsController, type: :controller do
       body = deserialize_response response
       expect(body[:name]).to eq(@team.name)
     end
+
+    it 'returns player account summaries when linked' do
+      player = create(:user, username: 'linked-player')
+      @team.players << player
+
+      get :show, params: { id: @team.to_param }
+
+      body = deserialize_response response
+      expect(body[:players].first[:id]).to eq(player.id)
+      expect(body[:players].first[:name]).to eq('linked-player')
+    end
   end
 
   describe 'PUT #update' do
@@ -46,6 +57,49 @@ RSpec.describe TeamsController, type: :controller do
         body = deserialize_response response
         expect(body[:name]).to eq(valid_update[:name])
       end
+
+      it 'associates an existing player account by email' do
+        player = create(:user, username: 'player-account', email: 'player@example.com')
+
+        put :update, params: { id: @team.to_param, player_email: player.email }
+
+        expect(response).to be_successful
+        expect(@team.reload.players).to contain_exactly(player)
+        expect(deserialize_response(response)[:players].first[:id]).to eq(player.id)
+      end
+
+      it 'creates a player account by email when none exists' do
+        expect do
+          put :update, params: { id: @team.to_param, player_email: 'new-player@example.com' }
+        end.to change(User, :count).by(1)
+
+        expect(response).to be_successful
+        expect(@team.reload.players.first.email).to eq('new-player@example.com')
+        expect(@team.players.first.username).to eq('new-player')
+      end
+
+      it 'associates multiple player accounts by email' do
+        first_player = create(:user, email: 'first-player@example.com')
+
+        put :update, params: {
+          id: @team.to_param,
+          player_emails: [first_player.email, 'second-player@example.com']
+        }
+
+        expect(response).to be_successful
+        expect(@team.reload.players.map(&:email)).to match_array(
+          ['first-player@example.com', 'second-player@example.com']
+        )
+      end
+
+      it 'clears player associations with blank player_id' do
+        @team.players << create(:user)
+
+        put :update, params: { id: @team.to_param, player_id: '' }
+
+        expect(response).to be_successful
+        expect(@team.reload.players).to be_empty
+      end
     end
 
     context 'with valid params as another user' do
@@ -58,5 +112,29 @@ RSpec.describe TeamsController, type: :controller do
         expect(response).to have_http_status(:forbidden)
       end
     end
+
+    context 'with valid params as linked player' do
+      before(:each) do
+        @player = create(:user)
+        @team.players << @player
+        apply_authentication_headers_for @player
+      end
+
+      it 'updates the requested team name' do
+        put :update, params: { id: @team.to_param }.merge(valid_update)
+
+        expect(response).to be_successful
+        expect(@team.reload.name).to eq(valid_update[:name])
+      end
+
+      it 'cannot reassign the linked player' do
+        new_player = create(:user, email: 'other-player@example.com')
+
+        put :update, params: { id: @team.to_param, player_email: new_player.email }
+
+        expect(response).to have_http_status(:forbidden)
+        expect(@team.reload.players).to contain_exactly(@player)
+      end
+    end
   end
 end
diff --git a/spec/controllers/tournaments_controller_spec.rb b/spec/controllers/tournaments_controller_spec.rb
index bfeefbf..8024e4c 100644
--- a/spec/controllers/tournaments_controller_spec.rb
+++ b/spec/controllers/tournaments_controller_spec.rb
@@ -608,6 +608,29 @@ RSpec.describe TournamentsController, type: :controller do
             post :create, params: data
           end.to change(Team, :count).by(data[:teams].count)
         end
+
+        it 'creates player accounts from team email values' do
+          data = create_playoff_tournament_data
+          data.delete :teams
+          data[:teams] = [
+            {
+              name: 'Alpha',
+              player_emails: ['alpha-player@example.com', 'alpha-partner@example.com']
+            },
+            { name: 'Beta' },
+            { name: 'Gamma' },
+            { name: 'Delta' }
+          ]
+
+          expect do
+            post :create, params: data
+          end.to change(User, :count).by(2)
+
+          tournament = Tournament.find(deserialize_response(response)[:id])
+          expect(tournament.teams.find_by(name: 'Alpha').players.map(&:email))
+            .to match_array(['alpha-player@example.com', 'alpha-partner@example.com'])
+          expect(tournament.teams.find_by(name: 'Beta').players).to be_empty
+        end
       end
 
       context 'with invalid parameters' do
diff --git a/spec/e2e/http/api_surface_spec.rb b/spec/e2e/http/api_surface_spec.rb
index cbd3600..258be34 100644
--- a/spec/e2e/http/api_surface_spec.rb
+++ b/spec/e2e/http/api_surface_spec.rb
@@ -118,6 +118,70 @@ RSpec.describe 'Backend API surface HTTP E2E' do
     expect(unauthenticated[:status]).to eq(401)
   end
 
+  it 'links player accounts to teams and exposes public account profiles' do
+    unless ENV['TURNIERE_E2E_ALT_EMAIL'] && ENV['TURNIERE_E2E_ALT_USERNAME']
+      skip('player profile flow requires TURNIERE_E2E_ALT_EMAIL and TURNIERE_E2E_ALT_USERNAME')
+    end
+
+    unique = unique_suffix
+    player_email = ENV.fetch('TURNIERE_E2E_ALT_EMAIL')
+    player_username = ENV.fetch('TURNIERE_E2E_ALT_USERNAME')
+    player_client = other_client
+    player_created_tournament = create_playoff_tournament(
+      client: player_client,
+      public: true,
+      name_prefix: 'Player Created'
+    )
+    tournament = create_playoff_tournament(client: owner_client, public: true, name_prefix: 'Player Profile')
+    linked_team = tournament.fetch(:teams).first
+    unlinked_team = tournament.fetch(:teams).fetch(1)
+
+    link_existing = owner_client.patch("/teams/#{linked_team.fetch(:id)}", body: { player_email: player_email })
+    player_update = player_client.patch("/teams/#{linked_team.fetch(:id)}", body: {
+                                          name: "#{linked_team.fetch(:name)} Player Rename"
+                                        })
+    player_reassign = player_client.patch("/teams/#{linked_team.fetch(:id)}", body: {
+                                            player_email: "stolen-#{unique}@example.com"
+                                          })
+    co_player_email = "http-e2e-co-player-#{unique}@example.com"
+    link_co_player = owner_client.patch("/teams/#{linked_team.fetch(:id)}", body: {
+                                          player_email: co_player_email
+                                        })
+    placeholder_email = "http-e2e-placeholder-#{unique}@example.com"
+    link_placeholder = owner_client.patch("/teams/#{unlinked_team.fetch(:id)}", body: {
+                                            player_email: placeholder_email
+                                          })
+    profile = anonymous_client.get("/accounts/#{player_id_by_name(link_existing, player_username)}")
+    placeholder_profile = anonymous_client.get("/accounts/#{player_id_by_name(link_placeholder, placeholder_email)}")
+
+    expect(player_client.authenticated?).to eq(true)
+    expect(linked_team[:players]).to eq([])
+
+    expect(link_existing[:status]).to eq(200)
+    expect(link_existing.dig(:json, :players).map { |player| player.fetch(:name) }).to eq([player_username])
+
+    expect(player_update[:status]).to eq(200)
+    expect(player_update.dig(:json, :name)).to end_with('Player Rename')
+    expect(player_reassign[:status]).to eq(403)
+
+    expect(link_co_player[:status]).to eq(200)
+    co_player_names = link_co_player.dig(:json, :players).map { |player| player.fetch(:name) }
+    expect(co_player_names).to include(player_username)
+    expect(co_player_names.any? { |name| name.start_with?('http-e2e-co-player') }).to eq(true)
+
+    expect(link_placeholder[:status]).to eq(200)
+    expect(link_placeholder.dig(:json, :players).first[:name]).to start_with('http-e2e-placeholder')
+    expect(placeholder_profile[:status]).to eq(200)
+    expect(placeholder_profile.dig(:json, :teams).map { |team| team.fetch(:id) }).to include(unlinked_team.fetch(:id))
+
+    expect(profile[:status]).to eq(200)
+    expect(profile.dig(:json, :name)).to eq(player_username)
+    expect(profile.dig(:json, :teams).map { |team| team.fetch(:id) }).to include(linked_team.fetch(:id))
+    expect(profile.dig(:json, :tournaments).map { |item| item.fetch(:id) }).to include(tournament.fetch(:id))
+    expect(profile.dig(:json, :created_tournaments).map { |item| item.fetch(:id) })
+      .to include(player_created_tournament.fetch(:id))
+  end
+
   it 'updates and destroys tournaments, enforces owner checks, and validates timer updates' do
     tournament = create_group_stage_tournament(client: owner_client, public: false, name_prefix: 'Mutable Tournament')
 
@@ -595,7 +659,13 @@ RSpec.describe 'Backend API surface HTTP E2E' do
     expect(response[:json].map { |match| match.fetch(:state) }.uniq).to eq(['in_progress'])
   end
 
-  def create_playoff_tournament(client:, public:, name_prefix:)
+  def player_id_by_name(response, name)
+    response.dig(:json, :players).find do |player|
+      player.fetch(:name) == name || player.fetch(:name).start_with?(name.split('@').first)
+    end.fetch(:id)
+  end
+
+  def create_playoff_tournament(client:, public:, name_prefix:, teams: nil)
     payload = {
       name: "#{name_prefix} #{unique_suffix}",
       description: 'HTTP API surface E2E playoff tournament',
@@ -604,7 +674,7 @@ RSpec.describe 'Backend API surface HTTP E2E' do
       starts_at: '2030-06-01T10:00:00+02:00',
       ends_at: '2030-06-01T18:00:00+02:00',
       website_url: 'https://example.com/turniere-e2e',
-      teams: 4.times.map do |index|
+      teams: teams || 4.times.map do |index|
         { name: "#{name_prefix.tr(' ', '')}-S#{index + 1}" }
       end
     }
diff --git a/spec/models/team_spec.rb b/spec/models/team_spec.rb
index d6d097e..33bcc69 100644
--- a/spec/models/team_spec.rb
+++ b/spec/models/team_spec.rb
@@ -9,6 +9,8 @@ RSpec.describe Team, type: :model do
 
   describe 'association' do
     it { should belong_to(:tournament).optional }
+    it { should have_many :team_players }
+    it { should have_many :players }
     it { should have_many :group_scores }
     it { should have_many :match_scores }
     it { should have_many :bets }
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 83ab130..0571095 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -5,6 +5,9 @@ require 'rails_helper'
 RSpec.describe User, type: :model do
   describe 'association' do
     it { should have_many :tournaments }
+    it { should have_many :team_players }
+    it { should have_many :player_teams }
+    it { should have_many :played_tournaments }
     it { should have_many :bets }
   end
 
diff --git a/spec/routing/accounts_routing_spec.rb b/spec/routing/accounts_routing_spec.rb
new file mode 100644
index 0000000..a6f008d
--- /dev/null
+++ b/spec/routing/accounts_routing_spec.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe AccountsController, type: :routing do
+  describe 'routing' do
+    it 'routes to #show' do
+      expect(get: '/accounts/1').to route_to('accounts#show', id: '1')
+    end
+  end
+end