The best for Man City is to sell Dzeko now, he have a high price, he scored a lot of the goals, and Mancini keep him on the bench, and that will just create a new Tevez case. I just watch list for top scorers in EPL, this guy is in the top five, even he have small number of the games, and he had in last two very important games less then ten minutes, so it is obvious that something is wrong with him and Mancini. Better to sell him now, than to keep him on the bench, and than bammmm, City have another Tevez case.
Mancini is wrong if he think that he will keep players like Tevez or Dzeko on the bench, and that they will be OK with that.
This guy was on the bench and in second City team, even when he was scored the most goals in City. So I don't see good future for team with him on bench. It will again blow up in Mancini face, just like Tevez. Nobody wish to seat on the bench, even if they have big money, sooner or later they will say, OK it is enough, and if Dzeko start to create problems like Tevez, City will not be able to get real price for him, so they will need to choose, sell him cheap, or pay him big money for nothing.
Sell him before is too late!