Senior Squad vs U21 Squad for young players

Hey guys,

I just bought an 19yr old left Fullback (Jonathan Silva from Estudiantes) in the winter transfer window. I now plan to let him play with the U21 squad for the rest of the season and only use him in the first team when both my left backs are injured/exhausted.

Now, does it matter to his development or his experience gains from U21 matches if he is marked and put into the U21 squad or kept in the Senior squad and just marked as eligible for all U21 matches for 90mins?

Does the momentary squad a young player is in affect him? Meaning U21 matches are more useful to young players in the U21 squad than to young players in the Senior squad? Or is it merely a help to keep things more clear?


And actually another quick question: I let Özil tutor Zelalem and his stats are improving quite a bit. But because Özil has only 9 Determination, Zelalem's determination fell down to 11 from 16 within a few months. Now my question: Will it recover again (slowly) as soon as I stop Özil tutoring him or is his determination decrease indefinitely? (without letting him be tutored by another player with high determination)

cheers!

First question, no difference.

Second question, I don't think it will go back up. Unless tutored again, obviously. As a attribute though, determination is overrated by a lot of people. It doesn't have any affect on player development (only ambition and professionalism do, which are both hidden).