Tevez signed for Juve last week.
Mancini told Tuttosport: "He's the type of player who has been missing at Juventus, one who allows the team to take a quality jump.
"It's never easy winning, but I think Antonio Conte has the team to win a third consecutive Scudetto."
On Tevez, he added: "In three-and-a-half years together he never gave me any trouble.
"My quarrel with him? There was a momentary outburst, and maybe at that time Carlos was thinking about leaving the club, but after that there were no similar episodes.
"Conte won't have a problem managing him because Carlos is a model professional."