It's not just this year either. He's been fighting it for a few years it seems. I'll admit that I don't watch a lot of Penguin games but he hasn't looked dominant in any game I have seen him in, in a longtime. That includes last years World Championships and the last Olympics. Who knows if there's anything going on between him and Lemieux or not. What we do know for a fact is all the awful injuries he's had over the years. It's disgusting how the league has pretty much ignored players cheap shotting him his entire career. Steckel got nothing for that first hit that gave him a concussion or broke his neck (whatever that one did). Dubinsky getting only one game for what he did to him last night was just as much of a joke.
On top of all that he plays for a team that has a medical staff that seems to have a lot of trouble diagnosing injuries and illnesses with him and his teammates. Maybe he's flat out just lost his passion for hockey in general and the NHL in particular.
Crosby has been first in the league in points per game every one of the past 5 seasons.
Bad first 23 games to start the year aside, he'll be fine and he'll be back to being the best player in the league sooner or later.