Im out of touch on this one. Do they want rid of him or do they want to loan him out? Also does he want to leave or does he want a loan for more game time?
Im not really a fan of his but mostly find the claims some are making about his ability to be a bit daft.
However players develop at different rates and because of different factors. He might have had a tough time in Germany because he struggled settling in another culture, he may have missed family and friends, struggled with the language etc. He may have been slow in getting used to new training systems methods and ideas, he is after still only 19. So he may want to leave because he is struggling with those sorts of things or he may be frustrated at the lack of game time.