He looks over the hill at 25,
so I wouldn't say completely unfounded. Then again, there were all those warning about Roddick's serving style making him prone to shoulder injuries, and that turned out to be the least of his problems.
But yeah, I think he does have more injuries than average, seeing he was injured at least 6 different times against Djokovic, and more against Fish, Dodig, and Tsonga etc.
Nadal has been second best player this year, and much better than the pusher from Scotland