While the former Manchester United striker has shown exceptional form this season, scoring 10 goals so far in the Barclays Premier League, he has at times looked ill at ease.
Tevez was upset with Mancini when he taken off with a minute left in the 1-0 victory against Bolton and ended up being shunted away by the manager. The Argentina international is also struggling with bouts of homesickness after being separated from his family.
Quotes attributed to the player from his spells back home in South America have intermittently appeared, seemingly questioning his long-term commitment to European football and referring to his disillusionment with modern football.
Yet Mancini has no doubts though that his captain remains committed to the club in the long term and said: "We can talk about this situation and talk about Carlos every week. I have explained it 1,000 times.
"Carlos is a fantastic player. He is one of the most important players in Europe and maybe in the world. He will stay here for a long time because he not told me otherwise."