Too late...he started.
@Twisted: I don't agree with Isabelle's characterization, but there's no reason for you, either, to hold the old line that there was nothing wrong with Nadal in the spring of '09, which doesn't have to take at all away from what Soderling did, or excuse Rafa's loss. But now that we're this much farther down the road we have the benefit of hindsight, and it is possible to mitigate our previous opinions. For example, I thought Roger was just gaming when he took a MTO v. Safin in the AO '05 SF, to have his back rubbed. But now I can believe that that was early signs of an issue that has troubled him. Surely you saw Nadal's knees taped much of 08 and 09, and you must believe now that he has chronic tendonitis. So he was playing with knee problems. Still, he might have gotten all the way through, if Robbie hadn't clipped him.
Soderling played one of the best matches of his career to beat Nadal that day, with the other one being the one he played to beat Roger the next year. It was a perfect storm of circumstances, IMO, the biggest being Robin's game. Another was the venom that he brought after that contentious match in Rome, which was far closer than the scoreline indicated; yet another was that it was heavy and chilly that day. Rafa didn't lose because his knees were bad. But he stopped after that because they were a mess, and he needed to take care of them...he was just going to keep playing on them until they gave out (which he says he didn't believe at the time,) or until someone beat him and he was forced to deal with them, which is what happened. In any case, he took the biggest scalp in tennis at that time: Rafa at RG. And everyone was shocked.
By the same token, Querrey played a really good match to get Novak on Sat. I don't think it takes anything away from him to say what we all saw, which is that Djokovic was jaded. Whether or not there's a shoulder issue, who knows. Most athletes hurt a certain amount most of the time. It hurts a lot less when you win. But my point is that it doesn't have to be completely b/w what goes into an upset. Sometimes there are a few things going on at the same time. Sometimes not: when Rafa lost to Kyrgios (W) and Roger to Cilic (USO) in '14, it was because each was just hit off the court.