Mancini admitted Bosnian forward Dzeko has been frustrated by his lack of opportunities - but he is certainly making an impact after grabbing a late winner against Tottenham.
He has now earned the champions nine points by coming on as a sub and is making a case for starting more regularly.
Mancini said: "Edin is not happy. But a player who is happy on the bench does not exist.
"We had three important strikers today, last year we won the championship because of goals from our strikers."