as EJ, Clementine and others have pointed out in different ways: whether one is tired or not is not simply a quantitative question based on time spent on court. It's also a qualitative question of what it takes out of a player emotionally and as others have eloquently explained to those too dense to see, the last few months will have taken their emotional toll on Andy. I'm still hoping he'll finish on a high next week but if he doesn't, can we please get behind him and support him rather than knock him down from the pedestal so soon? It was always unrealistic to think he'd do a Nole and win every match And this JJ guy is on a mission right now.
I'm not sure I'd go so far as Masaka as saying the early exits of so many top players were premeditated but I bet you as each one exited others may be thinking they don't want to be left behind in hot-footing it over to London. So such decisions - conscious or unconscious - have probably been made during matches when it didn't seem worth the candle of fighting back.
Good reasoned posting Ruthie. I know Djokovic won in the end but wasn't Toronto also something of a ghost town in terms of top players this year by the end? I guess the difference with that was the knock on effect was from the tournament before though (Olympics) rather than the one after.