Alot of things happend to him i think, last season, the manager refused to play him as a starter since he was gonna leave in a year, so he had 22 late subsitutes and that could kill alot of players. Another problem is that Juventus plays a system that doesnt fit him, so first of all he has to get back into match shape and after that he have to get used to a system that doesnt really uses him to his best abilities.
I think it would be a good move, because i think he would fit perfectly in our system and i think Wenger is a guy that can get the best out of him.