The Frenchman was impressive against Newcastle at the weekend, one of the few times Nasri has excelled at Manchester City under Mancini.
Mancini said: “I would like to give him a punch. Because a player like him should play like today always. Always. Every game.
“Maybe one game sometimes he can play [badly] but with his quality … I don’t know what was different on Saturday. I can’t understand [why] sometimes a player with his quality doesn’t play like today [in] every game.”