When a player is given a red card, or two yellow card in a match, he is sent off and will receive a suspension of a number of matches.

If you have instructed your players to tackle harder than normal, the risk of bookings and suspensions are higher.
Players can receive a suspensions of 1-4 matches depending on what he has done.

There is no distinction between league and cup matches. If a player is suspended during a league match, the suspension will also apply to cup matches and vice versa.

Players cannot be suspended in friendlies, and players that are currently suspended can play in friendlies.