I think it's physical most of the time with Özil. He looks incredibly quick, sharp and agile at the moment and he has done since the Everton game - which is when he returned from an injury. I knew he was going to come into form the moment I saw him throwing Everton players the wrong way without even trying.
He plays lots and lots of minutes and because of his style he can keep on trucking but he loses that sharpness I mentioned and it has a big impact on his game. He still has the genius but he's half the player when he can't unbalance markers to create space, and his touch isn't the same when he's heavy legged either.
People don't think it with Mesut -its always about his mood or motivation - but, he, more than most, needs to be fighting fit to really sparkle imo.