Balotelli, who joined the club last summer from Inter, has courted controversy this season for some of his antics on and off the pitch, incidents that have detracted from his ten goals for the club so far in all competitions.
But with some crucial games remaining in the season and injuries to many of his other strikers, Mancini hopes the 20-year-old can respond to the challenge in the right way - starting with the upcoming FA Cup semi-final against rivals Manchester United.
"Mario knows he must take more responsibility," said Mancini, who will wait to see if Carlos Tevez is fit for the game after limping off on Monday against Liverpool. "We have six league games, plus the semi-final and the final. I hope Mario can score important goals.
"He could be the hero. On Saturday, if he plays, he has a chance to do well. Maybe if he scores a goal it could take us to the final. That would change his year." Mancini also had encouraging words for January signing Edin Dzeko, whose troubles adjusting to his new surroundings the Italian compared to Chelsea's goalless forward Fernando Torres.
"We need Dzeko to be good now," Mancini said. "He has the same problem that Fernando Torres has at Chelsea.
"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."