He has been through 14 Manchester City managers and 38 derbies but Sir Alex Ferguson conceded that this might be the most important of them all. Only in the early years of his reign when he wrestled with an underperforming, overdrinking side have the red and the blue halves of Manchester met as equals.
However, should City make it into the Champions League, the United manager believes it could open a floodgate to the kind of spending that he could not and would not want to match.
"There is a definite emphasis on this derby game that has never been there before in my time here," he said. "It is the first time we have played City when they have a chance of actually achieving something. We always believe that we can get to Champions League finals but for City just being in the competition would be the most exciting thing ever.
"The thing is City can buy. They have such an amazing amount of buying power. They can go and buy another team. If they qualify for the Champions League, you can rest assured they will buy players. From our point of view we have a reasonable structure in place. We may need to tweak the squad here and there but we like to buy young players who we can develop – and we've been good at that.
"We have signed Javier Hernandez from Mexico and we may sign two more at the most – because that is the way we are. That is all we need. I don't think we will be in competition with Manchester City for players because they will be after different types of footballers."
Tottenham's first league victory in a north London derby for 11 years left Ferguson enthused not just because it knocked Arsenal out of the title race, but because it showed "they are definitely capable of beating Chelsea" this evening. However, that would be meaningless to the Scot without victory for United at Eastlands earlier in the day and, without their talismanic striker, United looked weary and disjointed at Blackburn last Sunday.
The risk of playing Wayne Rooney against Bayern Munich last week was justified by the way his presence seemed to galvanise Manchester United in the first half at Old Trafford – although, unsurprisingly given the damage done to his ankle in the first leg, his touch was awry.
"With Wayne we have to be 100 per cent right because this derby will be different to the Bayern game in the sense that it will be really hectic, particularly in the early part," his manager said.
Against him will be Carlos Tevez, who remarked towards the end of his final season at Old Trafford that he, Cristiano Ronaldo and Rooney could together form the finest attack in world football. Now there is just Rooney left and Ferguson, typically, had no regrets about not taking up his agent's offer to buy Tevez for £25m – despite the difference his 22 goals this season might have made at Old Trafford. "You cannot dispute he has had a great goalscoring season," Ferguson said. "I thought he had a good first season with us but in the second he didn't feature as much. He had far more competition with us than he has at City, there is no doubt about that.
"I have no regrets at all about Tevez, none whatsoever. We tried to buy him but we didn't match the money they [his agents] wanted, therefore the boy moved on. There is no bitterness for me. Players leave here; some do well some don't."
It was on an April day in 1974, the year United were relegated, that Denis Law's back-heel for City rubbed salt into their wounds. It was on a similar spring afternoon that City handed out the blue-and-white scarves that Roberto Mancini has made his trademark. Ferguson joked that for all the scarves displayed at what he used to call "The Temple of Doom" at Eastlands, Stuart Pearce's side did not actually manage a shot on target. It was 2007; United won, Pearce was sacked and City have fired another two managers since.
"We need to win, not because it is the derby but because this is an important game," said the latest, Mancini. "This last month is fantastic for us because we are going to play perhaps the most important games in the club's history." Those that saw City win the championship in 1968 at St James' Park on the final day of a season when United, their nearest rivals, stumbled at home to Sunderland might disagree. They finished second in 1977 and fourth a year later, too, although that did not seem to matter quite so much. It earned them a place in the Uefa Cup and a 3-0 win over Milan at Maine Road.
Under the circumstances, Mancini's pledge on succeeding Mark Hughes in December that he would qualify City for the Champions League in May and win the Premier League next season was a brave one. Just like the statement from Liverpool's incoming managing director, Christian Purslow, that he would make a club that now stands sixth in the table, "the biggest in the world", it can so easily be quoted back.
"I also said we would win the Carling Cup," Mancini said. He was asked what it was like to walk half the length of Old Trafford after Rooney's header in the closing seconds had dashed Wembley – and the promise that the banner on the Stretford End that marks City's years without a trophy would come down. "It was not a good feeling. We played a very good game that night and we did not deserve to lose and before his goal I thought that if we had extra-time we would win.
"I went to Ferguson's office afterwards and we talked about English football – and about wine. He was friendly." Of course he was, he had won.
Talking a good game: The war of words
*"Welcome to Manchester." Displayed on a city centre billboard last July with a blue-tinted picture of Carlos Tevez.
*"It's City isn't it? They are a small club with a small mentality. It is a go at us. They think taking Tevez away from United is a triumph. It is poor stuff." Sir Alex Ferguson responds
*"The manager has made decisions with players coming and going and has almost always been proved correct. He understands when a player's time is up." Gary Neville get his digs in.
*"[Gary] acted like a complete boot-licker, just to suck up to the manager. I don't know what the hell that idiot is talking about me for. What's the [moron] talking about when I never said anything about him. It was a lack of respect." Tevez responds after scoring against United in the Carling Cup.
*"When, not if we are at Wembley having beaten United again." City chief executive Garry Cook ahead of the Carling Cup semi-final.
*"I didn't think Carlos was worth £25m." Ferguson gives his reasons for not buying Tevez permanently.
*"If you analyse City you'd say 'what's their best team?'. They'll struggle to get into the top four. Sometimes you have a noisy neighbour and have to live with it." Ferguson
This season's meetings:
20 Sep 2009 (League): United 4 City 3
Michael Owen's 97th-minute winner denies City a point.
19 Jan 2010 (League Cup SF 1L): City 2 United 1
A double from Tevez cancelled out Ryan Giggs' opener.
27 Jan 2010 (League Cup SF L): United 3 City 1
Rooney's injury-time winner crushed City's cup hopes.Reuse content