Manchester City boss Roberto Mancini admits they could plunge Manchester United into crisis. City face United on Sunday in the FA Cup.

"After two defeats, maybe another one would be a problem," said Mancini. "But I still think they are very strong.

"I don't remember when I lost three matches in a row.

"Ferguson has won so many trophies but there are some periods when you have difficult times, when players are injured.

"At the moment it is very hard and in football, there are some situations that are very strange. But United has one very positive thing. Their mentality is strong.

"After one or two defeats, it is like it didn't happen. They start to play strongly again. Like after they lost to us, they won eight games out of nine.

"For this reason they are always very dangerous."