I am pretty sure Federer was drained last November after winning the TMC, he had to play Sampras two days later -- and then fly 5000km every day to another venue, three times in a row. The results that week (ending a defeat to Sampras) more or less prove what was happening. I definitely think he overextended himself around that time and may have left him susceptible to illness.
This may be so, but FEDERER also skips tourneys to take a rest so that's not it ... he takes his rest more than other players do.
All the same, why are people so hung up over his poor performance today?? GIVE FISH SOME CREDIT, he is playin some good tennis at IW.
Also Fedex just sucked maybe (did not see the match), but I am amazed of how people talk him down after just a few losses, come on stick with him if you also praise during the better performances.
BTW ... I do think his quote at IW site was ... hmmmm ... FEDEX should learn how to cash a loss with some dignity, that is also a part of being one of the GOAT.