Manchester United manager Sir Alex Ferguson has insisted he has no concerns over Wayne Rooney's 'natural reaction' to Vincent Kompany's tackle on Nani.
Kompany was sent off for the challenge in Sunday's FA Cup tie and the ten men of Manchester City went on to lose 3-2 despite a rousing second-half comeback.
City boss Roberto Mancini later claimed that Rooney influenced referee Chris Foy's decision to show Kompany a red card, an accusation which the United striker has rejected.
Ferguson has now backed Rooney in the row over what happened, highlighting his view that such appeals are now part of the game and that it was a bad tackle.
"I have no concerns about the behaviour in that respect because to my mind it was a reckless challenge and Nani is a very lucky boy because he didn't get a bad injury," said Ferguson.
"I have no complaints about Wayne, I don't think it was unacceptable what he did. I think it was a natural reaction to a bad challenge from an opponent.
"But I can understand where Roberto's coming from because that's what happens with players today, they all appeal for penalties or players to be sent off, it's an unfortunate part of our game."
Ferguson also said he was relishing a fight to the end of the season with City for Premier League honours.
He added: "We have a big challenge from Manchester City but that's not a problem for Manchester United, we have faced these challenges for many years. It doesn't matter where it comes from, Chelsea, Arsenal, Liverpool or Tottenham, and Manchester City are a very good team.
"We know it's going to be a big, big fight towards the end of the season."
Ferguson was speaking at the FIFA Ballon d'Or gala in Zurich, where he has been shortlisted for the Coach of the Year award along with Barcelona's Pep Guardiola and Jose Mourinho of Real Madrid.
Both Guardiola and Mourinho have been touted as potential replacements for Ferguson when he eventually leaves his job at Old Trafford.
Asked whether Guardiola would be the perfect man to come in when he does finally retire, the United boss questioned why the Spaniard would want to leave Barcelona whom he described as an "extraordinary team".
Ferguson added: "Why would Pep want to leave Barcelona? If I was in his position I would firmly stay where I was.
"The Barcelona team at the moment is by far the best team. We have experienced three years of it and sometimes in football you have to hold your hand up and say 'they are better than us'.
"It's not a crime or a weakness, just a plain fact that the Barcelona team now, particularly with Lionel Messi in the side, are just an extraordinary team.
"I can't see anyone taking a trophy for them this year, Real Madrid are probably the nearest to them."
Ferguson said that Messi could now be judged alongside the greats of world football through the ages, even though he is still only 24.
"I would agree with that completely," said Ferguson. "Critics have always questioned whether players like Pele from the 50s could play today.
"The answer to that is great players would play in any generation. Lionel Messi could play in the 1950s and the present day, as could (Alfredo) Di Stefano, Pele, (Diego) Maradona, (Johan) Cruyff because they are all great players.
"Lionel Messi without question fits into that category."
Ferguson believes Barca will win the UEFA Champions League again this season, adding: "I can't see anyone taking the trophy from them.
"Sometimes in football you have to hold your hand up and say, yeah, they're better than us."