Man City boss Mancini: Time for Dzeko to come good
Bought from Wolfsburg for £27million in January, the Bosnian has struggled to adapt to life in England, hitting the net on just four occasions, all of them in cup combat.
He does have scoring form against United though, bagging two against Sir Alex Ferguson's men in a couple of Champions League meetings last term.
"We need Dzeko to be good now," said Mancini.
"Dzeko is a fantastic striker but when you join a team in January, he has new team-mates and a new manager with new methods."