Manchester City will today learn if captain Vincent Kompany will miss the club's next four games after being red carded during Sunday's FA Cup tie against Manchester United.
The Belgian defender was dismissed following a two-footed tackle on United winger Nani at the Etihad Stadium, a decision that Mancini has lamented.
Gael Clichy's sending off against Chelsea and Gareth Barry's dismissal in victory over Liverpool both came in controversial circumstances, and Mancini feels his side are being hard done by.
"It is strange. In England now there are a lot of red cards for nothing,” said Mancini.
"Vinny did nothing but usually they give a red card for nothing – for Clichy against Chelsea, for Gareth Barry. I do not understand this."
"My opinion has not changed. I am confident because Vinny only played 10 minutes," he added.
"He was sent off for nothing. He has already missed one game.
If the ban is not upheld by the football association, City face being without their skipper for both legs of the Carling Cup semi-final against Liverpool, as well as the league matches against Wigan Athletic and Tottenham Hotspur.
The loss of Kompany is compounded by the loss of both Yaya and Kolo Toure for the African Nations Cup, which could see them miss over a month of action.