everyone has been well below par since the CC final, so it's unfair to single out Nasri.
having said that, I was never one to go overboard with the Nasri praise this season. He was good but never looked capable of carrying us when the chips were down, which is the mark of a truly great player. Same goes for Djorou, who I'm still unconvinced is first team material.
I think it's symptomcatic of a larger problem, that is, that most successful teams have at least 2-3 of their big players fit and firing at the end of the season. Rooney was nowhere at the beginning of the season for United, Nani was carrying them, now Rooney's come to fore again. Not one player has had durable enough form to sustain us for the run-in.