Obscene amount of yellows

My center backs are getting tons of yellows throughout the season, I usually play them man marking and for specific instructions against opposing players, I usually don't have them hard tackling the strikers, but they still get booked. Anything else I can do to limit their amount of cards?

Also, how many matches does one get for 10 yellows? I thought it was two but one of my CBs just got his 10th yellow and now he has a 3 match ban? Playing in the second season now. He has never been red carded this season either

Possible factors:

Aggression - while defenders should be aggressive to certain amount, then being extremely aggressive means more bookings. Aggression attribute around 10 is reasonable. It should be between 10-15 for defenders. Disciplining your players for violent/unprofessional behaviour after they get sent off in a match might lower aggression attribute.

Skills - good tackler is mostly playing ball, not men. When he lacks skills and opposition strikers pace, technique, agility are too good, then defenders make more fouls.

Referee - obviously you have noticed that in one game you play 90 minutes without any bookings and in other one ref is giving at least 4-5 to each team. You should be a bit more cautious about hard tackling and opp. instructions when the referee is harsh one.

See if your CB's have the preferred move "dives into tackles" in their profile. If the have, interact with them and ask them to "stay on your feet whilst tackling" or word like that. I had the same problem and found this cured it.

Mate, i signed sakho from french football, he is a god in stats but the psycho has been booked 17 times and sent off 3 times in his debut season!!!!

Chopper incarnate.