Messi has this kind of character that he needs to feel supported to deliver his best. Call it negative, weak or whatever you like, that's his personality. Messi is always Messi. Even if he has a bad game he might show some magic in one moment and change the course of the whole game. But overally, I got the feeling that the players that are playing beside him upfront right now are not in that level that Messi feel secures around 'em. Messi is a demanding player. Alexis Sanchez, despite all the orgy people have for him in here, and showing some flashes of brilliance during this season is still far from that reliable undisputed part of the Barcelona strking force and Cuenca is just a young lad. Villa, Pedro and Iniesta are all out, so Messi is feeling more and more pressure on his shoulders to lift the team forward and scoring goals.
Messi both needs the trust of his team-mates and to trust his team-mates to deliver his best. That's his character. I don't rule out that he can be tired as well (as I'm sure he is), but on a bigger image, that's how I see it is now regarding his current situation. He has the same case with Argentina, where it's even a bigger mess, and that's why Messi's performances for Argentina are far from the ones that he has with Barcelona. Messi needs security, both in his head and around him to be the great Messi we all know. The more secure he feels, the better he performs. And vice versa.
