Dzeko himself had words with his manager after leaving the field and appeared to throw down his football boots and tracksuit top, as well as aiming a sarcastic thumbs-up to the bench.
There was a stern warning from Mancini for the giant Bosnian.
"This is the last time one player leaves the pitch and moves his head like this," Mancini said.
"I can understand a player is disappointed. I can understand inside he can be upset if he thinks he has played well. But I am the manager. I decide everything."