Well, La Liga is much less physical. It was obvious today that he can be bullied off the ball really easy. Another thing, he's played out of position and he doesn't get enough rest.The Ozil case is a really odd one, I thought he'd thrive in this league but maybe he suits a more direct team.
Disappointing though, I think the bigger questions are why you didn't invest more in the summer, at least get a Defensive Mid in if nothing else.
On the pitch he looks like 17 y/o talent, glimpses of magic, but overall ineffective and off the pace.