For all players with statistics attached, we recommend creating a new hidden team called Past players, then simply moving the player from the existing team, to the Past players team.
To move a player between teams:
Login to your Club Control Panel.
Click the Membership tab.
Click Membership Database in the left side menu.
Find the player within the database and click on their name to bring up the player details.
Click the Roles tab.
Remove the existing player role, and add a new player role for the Past Players team. Click Save.