The Manchester City boss is hoping that the Red Devils qualify as he believes a Wembley match-up between the two best sides in England would be an ideal end to the season
The Citizens made it into the semi-finals with a convincing 5-0 win over Barnsley, courtesy of a hat-trick from Carlos Tevez and a goal apiece from Aleksandar Kolarov and David Silva.
With the Red Devils set to take on Chelsea in their quarter-final clash at Old Trafford on Sunday, Mancini has expressed his desire to see Sir Alex Ferguson's men triumph in order to set up a showpiece derby in the final in May.
"I don’t know who we will play, it could be [Manchester] United, Chelsea, Wigan - when you are in the semi-final or the final of the FA Cup you play against good teams," he told reporters.
"It [a final between Manchester United and Manchester City] could be perfect because in the last two years United and [Manchester] City have been the best teams in England."
The Italian was in defiant mood as he refused to concede defeat in the Premier League, while also declaring his team's intentions to make it to Wembley twice in the FA Cup.
“The Premier League has not finished - we never give up, we have to win the next game to get to the final of the FA Cup and if we win the competition it will be a great achievement," he continued.
“It is good to play at Wembley and this is the second time in the FA Cup and we want to play there twice if it’s possible."