The enigmatic Balotelli has created as many headlines off the field as on it during his two seasons at the Etihad Stadium and shown his undoubted talents only fitfully.
But the 22-year-old proved what he can really do with a starring role in Italy's run to the European Championship final, capped by a superb two-goal display against Germany in the last four.
City boss Mancini was impressed but knows it is difficult to replicate the intensity of a short tournament over a nine-month season.
Mancini said: "The European Championship is like the World Cup. For one month every player does 100%.
"Probably this championship can help him to improve but I don't think he can change in one month.
"But Mario is an important player here. I think he can do his job here better but I am sure that he will do."
Due to the European Championship, Balotelli was one of the later players to return for pre-season training.
He did not feature in the Community Shield win over Chelsea a fortnight ago and was a substitute as the champions began their Barclays Premier League title defence against Southampton last week.
There could be an opportunity for him to return to the side at Liverpool, though, following injury to Sergio Aguero.
If he is given a start, it will be his first for City since his sending off at Arsenal in April and continue his turnaround since that nadir.
Mancini appeared to have lost patience with the 22-year-old after that red card, which came in a crushing defeat and seemed to have cost City the title.
City recovered and Mancini eased his tone, and now the manager seems fully behind his compatriot and protege again.
Mancini said: "Mario has a big responsibility here. For us he is an important player. We spent a lot of money for him.
"He has done very well for Manchester City and in two years he has won the FA Cup and the Premier League. I think he did well.
"But I agree if Mario plays always like he played in the European Championship it would be better."
While Balotelli could combine with Carlos Tevez in attack, Mancini will also be hoping his defence can stop recent leaks.
City conceded four in the victories over Chelsea and Southampton and needed to come from behind to win both games.
Mancini said: "In the last two years we were the best defensively but you can be the best defence not only because you have good defenders, but because all the team are working for the defensive phase.
"I don't think there is a defensive fault if we concede four goals in two games.
"I think we made two or three mistakes but this is possible in the first two or three games.
"It is clear we need to improve, we need to work, but last week we worked only one day before the game."
Inevitably City have been linked with a number of players as the summer transfer window draws towards its closure next week.
Defenders and defensive midfielders have featured among the speculation but Mancini has given little indication of his thoughts.
Inter Milan's Brazil right-back Maicon, a player Mancini knows from his time at the San Siro, has been mentioned but the manager claims he knows nothing of it.
He said: "I don't know. I bought Maicon when he was at Inter, but now he is an Inter player. No (no interest), not at the moment."
Despite that, City are expected to make moves into the transfer market, particularly after the sale of winger Adam Johnson to Sunderland.
Mancini said he would not sanction departures without having replacements lined up as he does not want to reduce the size of his squad.
Yet after spending some lavish sums over the last four years, finding value for money is hard.
Mancini said: "For us it is more difficult because every club, when they talk with us, start from £30-40million.
"This is not correct. Maybe you can pay more but not so much."