The Italian has not been able to make full use of his star-studded squad with injuries to key inclusions Mario Balotelli, Aleksandar Kolarov and Jerome Boateng and he will be forced to wait a few more weeks after Balotelli and Kolarov suffered setbacks this week.
"It's about time Mario comes back, and fast," said Mancini. "He is recovering. All is normal. There are those who come ready a week earlier and those a week later.
"He has had his knee checked by the specialist in Pavia and again last week. We are just waiting for him to return now.
"Without flying full-backs like Boateng and Kolarov, who can push forward, I've had to adjust the team in order to get results and stay in touch with the leaders until everyone is back and fit," added Mancini who has the Eastlands club sitting second on the league table.