Many of us think it's a confidence problem that he is having right now. He seems to have good weeks like, say, Queens/Wimby or Washington DC or Houston and then follow up with something crappy (Indy, Montreal, or Rome, respectively). Some of us think he needs a sports psychologist - at least try it and see what happens. We know his game is improving and that he's in good shape, and we don't like to see him lose matches we know he could've or even should've won. But he's not really hitting with conviction or authority or confidence right now and so his shots are weaker and are sitting up and so his opponents are able to tree off on them and smack winners.
We hope he snaps out of it - sooner rather than later would be good
But of course he should do well at the USO - he hasn't lost before the QF there since he was a real pro (I don't really count 2000 when he was 17), so losing any time before the QF would be a big disappointment IMO. The rest would depend on his seeding and draw. If he's seeded 4, I'd expect him to make the semis but if he's seeded 5 and draws Fed in the Quarters, well the.... lol.
I believe he's capable of winning it, tennis-wise, but mentally I don't think he's in the right place right now.