I personally would not be able to deal with it as I no longer member of the M.L.
However I would expect clubs to play in the spirit of the game.
Its VERY hard to detect some one who's played under assumed name,unless you have photo of team, booked and gives wrong name to referee.or get injured taken to hospital. He may then follow the club which would leave the club in a be-caress position.
However had found a club in this position number of years ago who did get caught, and ended up paying for there crime. I would like to think it doesn't happen today.Because of the cost,:D it could end up on a club.:)