I just watched the match again and have to say that Messi did alright. No way we had won without him. He may not have been as brilliant as we are used to seeing him play, but was fully committed to help the team and fight, even in defense. He was fouled and harrassed throughout the match by Illaramendi but still created chances for Neymar and Suarez. How about his backheel that almost resulted in a goal by Neymar? He did not try to get any personal glory, except maybe with the freekick (he did earn himself) that missed the crossbar by a very small margin.
He got a yellow card for delaying the game, but did much more by stabilizing the midfield, in particular when Iniesta was out of the game.
Overall, a very good effort to help the team overcome the curse. It was not the kind of game for Messi to experiment with a limited RW role instead of optimizing the number of touches to gain control of a very choppy game.