I don't think Balotelli should be playing wide left either, that's half the problem. He's never going to be a player that tracks a ridiculously energetic fullback like Sagna up and down the pitch. Few strikers would/could. He needs to play through the middle, as the focal point. Problem is, I don't think he's quite ready for that. Not ready to battle with 6'4" centrebacks the way we see Robin trying to do every week. Mind you, Aguero hardly broke sweat on Sunday either, if anything I'd say Balotelli looked like he was far more up for it and interested than the little Argentinian was.
In fact, if it was up to me, I'd play Balotelli through the middle and force Aguero to play wide or drop him to the bench. Especially in away games.