The Argentine emerged from the bench to assist Samir Nasri's winner in the second half in what was his first appearance in six months.
Mancini admits the front-man is still some way from full fitness, but is confident he will win over the fans during the title run-in.
"I think it was important that Carlos made an incredible assist for Samir and all the supporters were happy with that," said Mancini.
"I think Carlos needs more time, it's not easy for him but it's important that he is here now.
"Maybe in 10 days, two weeks, he can find good form. I think that will be important for us.
"Carlos is maybe not 100 percent but he knows football and he was important because he was incredible for us.
"I have spoken with Carlos every day this month and he knows he had to come off the bench and play 20 minutes in this game but he can play more in the future.
"He's an important player, he needs another two or three weeks to have good form but when he plays, he knows where to take the ball."
The Italian added that any ill-feeling between himself and Tevez was finished, despite the City boss claiming the striker would never play for the club again.
"That was finished a month ago when Carlos came back here," added Mancini.
"Now it's important for Carlo to play some games for us, for him, for his future."
