Tevez, 27, was inspirational as skipper last season, scoring 23 goals for City as they ended their 35-year trophy drought by lifting the FA Cup, as well as qualifying for the Champions League for the firsty time in their history.
But after repeatedly stating his desire to leave City and move back to South America to be closer to his family, the Argentina striker has been stripped of the armband.
"The captain is Vinny Kompany," Mancini said. "The reason is simple. Carlos in the summer wanted to leave the club for family reasons. I respected his opinion to leave the club. But Carlos is here now, we didn't find any solution for him.
"He is a fantastic player for us because he can score 20 goals in one year - but I decided in the summer Vinny was the captain.''
Tevez has been City's top scorer for the past two seasons but now appears to be behind Edin Dzeko and record signing Sergio Aguero in the pecking order.
Dzeko, who struggled to make an impact in the second half of last season after his £27 million arrival in January, has been in particularly good form. The Bosnian has scored seven times in four appearances this term, including one in the Community Shield and a hat-trick against Tottenham.
Mancini said: "Edin is a fantastic striker, he scores everywhere. I am sure that this year Edin can score a lot of goals for us.''
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