The enigmatic Balotelli's ability is beyond question, but the 21-year-old is just as capable of the bizarre and he made an impromptu appearance at an Inter Milan press conference during the week, when Andrea Stramaccioni was unveiled as the new manager of his former club.
With Sergio Aguero sidelined with an injury and Carlos Tevez striving for match fitness, Balotelli looks set to be handed an increased role in City's championship challenge, but Mancini knows he cannot rely on the Italy forward. "I don't trust Mario. No-one trusts Mario," he said.
Mancini added: "He is a top player. He can do everything. He can score two goals against Arsenal next week. But he can also take a red card.
"Until now he did well and in the last eight games he could be important for us. But trust him? Never."
Not even to remain in England when he is given a couple of days off, as was the case this week.
"I can't put him in his house for two days," said Mancini.
"Probably the moment will arrive when he will know what he should do when he has two days off.
"I hope he will grow out of it because he needs to know this is his job. He needs to work and rest. But he is young."