"City often appear to lack enthusiasm when Tevez isn't in the side, " observed Rosler, who scored 50 goals in 153 games for City and since retiring as a player has manager Norwegian sides Lillestrom, Viking and Molde.

BBC: Why Carlos Tevez is so important to Manchester City

"The only thing that worries me is that he has come out in public a few times to say he misses Argentina, he misses his family, he thinks about retiring, " said Rosler, who plans to move his family back to Manchester having completed a successful two-month stint at Molde.

BBC: Why Carlos Tevez is so important to Manchester City