Not that this most basic and bitter of hostilities will have diminished over the past five years, as the huge police presence indicates.
Carlos Tevez to play with juniors after outburst at Manchester UnitedSir Alex Ferguson will play a full-strength team Sunday, giving the opportunity to his young players at Eastlands on Wednesday, despite the prospect of Manchester City reaching a first major cup final since 1981, the same year that Leeds last won at Old Trafford.
At the start of the campaign, Ferguson would surely have swapped both the FA Cup and the Carling Cup for winning either the Premier League or the Champions League and although Leeds require a level of seriousness, he is not put off continuing with his fringe men against City, despite the backlash felt by Arsenal when their kids were knocked out at this stage by their bitter rivals Tottenham last season.
Spurs went on to lose to United's youngsters in the final last year and that gives Ferguson the confidence to go into the game with Robinho and Carlos Tévez, who beat Arsenal 3-0 in the quarter finals, with the Da Silva brothers, Danny Welbeck and Darron Gibson.
"The younger ones will play," he said. "Our fans don't want to see us lose. There is no intention to lose either. They all played in the FA Cup semi-final last year against Everton and should have won the game. They proved themselves by winning the Carling Cup final against Tottenham. They excelled.
"City will play their strong team, that is right, but so did Everton and Tottenham. We have to do what we think is right. We shouldn't be picking a team because City are saying they are playing their strongest team.
"The young players have proved themselves. We use the Carling Cup as a route for young players, and they have all done well. I don't need to change that."
The importance attached to this game across town at Eastlands is indisputable and although winning a first trophy since 1976 would be seen as merely an indication of progress by the club's hierarchy, the timing could not be better for a semi-final victory against such opponents as they look to build bridges after Mark Hughes's departure last month.
Roberto Mancini has enjoyed a decent start in the Premier League, with two victories and two clean sheets, and while it is only climbing the table that will keep him in a job, the two-legged United semi-final offers the chance to win over any supporters still pining for Hughes.
Months after the intercity row over posters and Tévez that saw Ferguson claim that City are "a small club with a small mentality", the United manager, made his feelings clear about Hughes' sacking last month, describing the behaviour of the club, also branded his ''noisy neighbours'', as unacceptable.
While City have Mancini, his Italian styling and enormous scarf, Leeds have Simon Grayson and his bad trainers. The Yorkshireman, whose team top League One in their third season there, would prefer promotion to the Championship to winning the FA Cup itself.
On the pitch there should be no contest but the match has been categorised as 'increased risk' by Greater Manchester Police, for good reason.
"There are all these rivalries with Everton, Liverpool, City, Leeds from years ago," Ferguson said. "They are always intense. I was quite surprised at the intensity of the Leeds games when I first came down here. I didn't know where they came from.
"It emanated from the 1960s when Denis Law used to cause all those problems, punching players. There was that great photograph of Denis with Jack Charlton, Denis' strip is ripped right off him and they are all piling in.
"So obviously there was some intense feeling back then and I used to say to the players to make sure we behave properly on the pitch. We don't need to add to the problems and the police obviously had a difficult day."