Balotelli did not play having missed some training sessions this week through illness.
Mancini was not concerned about reports the 22-year-old had been spotted elsewhere in Manchester on Saturday.
He said: "Mario is ill. I don't know where is now. For one week he was ill.
"He came to the training ground yesterday because he wanted to train but he couldn't. I can't close him in his house, it is impossible."