He was instrumental in many (most?) of Argentina's goals, and had to play in a style very different to how he normally plays for Barcelona. The only real criticism you could level at him was his lack of goals, which is fair enough. He forced some of the best saves from goalkeepers at the tournament, but no goals is no goals.

Compare this to, say, Ronaldo who was also forced to play in a different way, and was considerably less adept, at it, and notably frustrated.