Tevez scored only four goals last season and spent much of it AWOL back in Argentina after his Munich night of shame.
But if he can return to the form he showed in scoring 54 goals in his first two campaigns with the Sky Blues, he will be like a new signing for Mancini.
The boss said: "Carlos has worked well. His form is better than last year and he's 100 per cent fit. I'm happy with him."