full back bookings

[beems]

Not sure if I'm doing something wrong althoughy tactical instructions are generally blank, and I normally only change the mentality ie attacking or counter etc. But my full backs regardless of who play there keep picking bookings up virtually every match. I'm playing as chelsea and have 1st season Azpilicueta at right back and Rahman left back and they were suspended at least twice each purely through totting up bookings in the first season, and again in the 2nd season I'm half way through and both have been suspended for totting ups again and are also prone to being sent off for 2 bookings, Azpilicueta had a game where he scored got booked a minute later and sent off 3 minutes after that. I've also used Ake at left back in the 2nd season who keeps getting booked too. Now obviously bookings happen but it only seems to be whoever plays full back. I mentioned it on twitter and they directed me to the bug forum however I don't think I'd classify it as a bug just wondering if I'm doing something wrong?