Andy has now seen his 4th loss to Nole this year alone. While Andy is still a level below Nole, this loss in retrospect, isn't really a big deal. I haven't seen the match (I have recorded it - not sure if I'll watch it in the end) but I believe it's a combination of things that saw him the loss today. For instance, he's got to be a bit tired by now and the fact that he's qualified for WTF after his straight sets win over Dimitrov must have taken away some of that motivation. I don't think he was very focused today against Nole, as he had one too many breakpoints against him unlike his previous matches and of course, take in the fact that, Nole still is the best player in the world so one must bring their best to face Nole. I don't feel the whole package was there today.
Anyway, he still has WTF to look forward to and he'll be much fresher by then and a good showing there would help his ranking come 2015 AO and that's the main goal. While a win over Nole would have been really nice, WTF is still the place where Andy should bring his absolute best. At the very least, I would want Andy to make sure he's there where he is right now in the ATP ranking.
Good points. I saw the match and it is just as you surmised. Tired, unmotivated, and wasn't that aggressive, like he was in the Grigor match. Hopefully, he'll recover in time for the WTF. I miss the old Andy.