The French midfielder appeared to headbutt Canaries defender Sebastien Bassong but his boss feels that both players are as guilty as each other, making his player’s dismissal unfair.
But Mancini revealed he is still disappointed with Nasri’s actions during the tussle.
He said: “Samir said that he moved his head towards him but the other player did the same. We will appeal because for us this is not correct.
“If the referee decides to send him off it’s for both players, or maybe it’s a yellow card for both players. It’s not a red card [just] for Samir, but I think Samir did a mistake. He made a big mistake and I’m disappointed with him.
“In the end we won and we are happy.”