The onus will be on the young Italian following the injury top scorer Carlos Tevez picked up in the 3-0 defeat to Liverpool on Monday night.
Mancini believes Balotelli is capable of filling the Argentine's boots, and believes this weekend's clash with their local rivals could be the time to do it.
He was quoted as saying by The Sun: "He could be the hero. On Saturday, if he plays, he has a chance to do well. And if he scores a goal that can bring us to the final, he can change his year.
"He has the big-game mentality to do it.
"In the previous game against Sunderland he played very well. But against Liverpool, after it became 3-0, it was difficult for all of the players.
"In the next six league games - and in the semi-final and final - I hope Mario can score goals."