The City captain was sent from the pitch in the 75th minute for a challenge on Jack Wilshere but the fact he won the ball has prompted Mancini to try and have an unnecessary three-game ban thrown out.
"We will appeal, because it is impossible that we can lose one player for three games for nothing. It is not red card, it is nothing," said Mancini.
"He went into the tackle, anticipating the opponent and took the ball before.
"I don't know how it is possible to get a red card like this. It was no foul, no red card.
"He went in with one foot, that is a tackle. If you want to be right and just, we can say what has happened - if it was a red card, I would say, but it was not a red card, because he anticipated Wilshere. Totally, 100 per cent."