Can tutoring make your players worse ?

Just wondering if I can actually make my players worse by tutoring them?

Also any idea why I cant tutor my 20 and 23 year old gks ??

Yes, if the tutor has poor mental attributes, particularly professionalism and determination.

Same as Athos, make sure the tutor has good Mental/Personality type. Determind, Model Professional, Leader are good personality types to look for but if the tutoree has the complete opposite i think they just wont get on and the tutoring will break down. Also if your GK's have been playing first team football or have high reputations then they will unlikely take to tutoring. Also i think they cant tutor if either they or the tutor is learnng a PPM, cant remember which way around it is or if it counts for both of them.

Just wondering if I can actually make my players worse by tutoring them?

Also any idea why I cant tutor my 20 and 23 year old gks ??

As athos mentions, you can do more damage than good, if you do not pick your tutors with care ... if your youngster have better hidden stats than the tutor, the tutor will drag his stats down. Basically the youngster's stats will move towards the tutor's stats (they will never exceed them).

Also the reason why they can't be tutored can be many. In FM11 youngsters cannot be tutored once they are 23 years old. So that excludes one of your keepres. As for the other one, if his reputation or squad sttus is higher than your tutor's, then he can't be tutored (by him).

Here is a little information on tutoring in FM11: http://community.sigames.com/showthread.php/249474-Tutoring-FM11-new-tests