I mentioned earlier that I was not sure if cards disappeared from your deck once their contracts hit 0 games remaining. I ran across this MUT FAQ earlier this morning.
– It’s a good idea to have some Contract Extension Cards on hand when your player contracts start running low. If you have players that are down to a single game contract, the next time you exit a game they will expire.
– At that point, you’ll be asked to extend the contract before the player is removed from your team. If you are out of contract cards at that point, you’ll lose the player whose contract has expired.
That sort of makes sense; you can wait until the bitter end, but you better have enough contract extensions (of the right card type – Bronze, Silver, Gold, etc) on hand to extend anyone you want to keep around.
The FAQ also has some useful information on how team chemistry affects your overall ratings during a game.