It's too easy to say that his form has been down to not playing in the centre. He has played in the centre plenty of times for Arsenal and has still struggled. His form hasn't been great for both Arsenal and Germany over the last year. He was Germany's top scorer in their qualifying campaign for the World Cup but he was quite average by his standards in the tournament itself. He played excellent today and hopefully he keeps it going cause he's a wonderful payer to watch.
Forced out of position for Germany (and have Kroos next to him and Mueller, with whom he has incredible chemistry, on the other side), and one could see how much our offense suffered because of it most of the tournament, though there is an argument that it had to be done because of injuries (I disagree.), and at Arsenal last season he didn't get nearly enough runs runs from his teammates. The player types next to him were wrong most of the time, and that certainly made his first season that much harder. You can't drown Oezil with the Cazorla, Rosicky, etc. player type next to him and expect him to do what he's best at. It was frustrating to watch. He needs closer to the Walcott, Schurrle, etc. player type. Doesn't even have to be that caliber or exactly that type. Just closer to it. Get him more runs in front of him. He's going to have much more of that season. I expect him to excel. IMO, the MAIN reason for his struggles have been position and players types next to him. I'm not saying that he couldn't have been better anyways.