c# Fluent Builder with Generic?

Looking for advice on best practice.

I have a fluent builder class (reduced complexity to highlight issue)

public class GameBuilder : IGameBuilder
{
  private readonly Game : game;

  public Game AddPlayers(List<Player> players)
  {
     game.SetPlayers(players);
     return this;

  }
 
  public Game Build()
  {
     game.Initialise();
     return game;
  }

}

This is great as I can build up a game with different arguments. Now unfortunately my SME told me that I can have a game with Supremo Players.

Supremo Players have extra data associated with their class so immediately I thought no problems I will inherit from Player but I'm not sure if this is right. I guess I could use generics on the builder but I would need an example to help me :)

The rules: A game can only have one type of player The player type is known at constructor time.

Any guidance appreciated.