Tevez could leave City in the winter transfer market after his latest falling-out with the club.
Tevez returned to his homeland earlier this month without City's permission and has yet to report back to training, having previously been punished by the club for refusing to warm up during the Champions League game away to Bayern Munich.
Reports in Italy have strongly linked Tevez with a move to Serie A, with Inter Milan, Juventus and AC Milan reportedly keen to sign the 27-year-old.
"Tevez is strong regardless of what has happened," Mancini told Italian television station Rai Due. "And great players have a price that is rather high."
Mancini denied speculation that City are in talks to acquire Napoli forward Edinson Cavani.
Cavani is a reported target of the Blues, who face Napoli in the Champions League.
When asked about City's reported interest in the Uruguay international, Mancini said: "The good players are all interesting but there's nothing.
"We can't buy every player."