Roberto Mancini has warned that Manchester United are likely to come out fighting when they face Manchester City on Sunday.

Mancini's City triumphed 6-1 the last time the teams met, but the Italian has warned that United will be angry coming out of two straight defeats to Blackburn and Newcastle.

"Derbies are always difficult and, at this moment, maybe even more so because they are angry about two defeats," Mancini said. "It is one game United will play to win.

"They are a strong team, a good team with very good players. They have a lot of injuries but at Newcastle they still had a good team on the pitch.

"After losing to us they won eight games and drew one. That is why they are always dangerous."

Mancini added that fans of both teams should be happy that their two teams currently dominate the top of the Premier League table.

"For the city of Manchester, it's important to have two teams like we have at the moment.

"In the past they had only one but now Manchester has two important teams and that is important for the city."

The rivals face off in the third round of the FA Cup at the Etihad Stadium on Sunday.