It's hard to say. He may just be burnt out. I think he's played uninspired all year. He's had times when he's come out in the first couple of matches and seemed to be on track and by the third match he's back to seeming less interested than in the past.
It's rare that you see him even fist pump. I really don't know, but I do think he'll get it together. He has too much pride not to.