Manchester United manager Sir Alex Ferguson has admitted Manchester City are now one of his club's major competitors.
While Liverpool, Chelsea and Arsenal plus, briefly, Blackburn and Newcastle, have gone head-to-head with United during Ferguson's glorious reign, City have been little more than an irritant.
Although they have occasionally managed to get in a pretty fierce blow; the 5-1 win at Maine Road in 1989 was pretty sore, as were the 3-1 and 4-1 defeats immediately before and after the Blues' move to Eastlands, as a threat to the United honours board they were not even on the same radar screen.
Now times are changing.
United's supporters will emerge from their naval gazing at a fairly chronic financial situation to confront their ironically cash-rich neighbours in the Carling Cup semi-final.
Victory for City in the two-legged encounter would put them into a first major domestic final since 1981 and within touching distance of their first trophy in 34 years.
It is a position the Red Devils desperately want to avoid. Yet, as Ferguson acknowledges, given the vast sums being invested from Abu Dhabi, it does not appear they are going away.
"You have to recognise they are a competitor now," said Ferguson.
"We have had to wait a long time for it to be like that but they are obviously making a much better fist of their league programme this year than they have done in the past.
"You could not compare it to Rangers and Celtic but having rivals in the same city does create far more emotion."
Not that Ferguson expects the same intensity at Eastlands tomorrow as he endured in September when a Michael Owen winner in the sixth minute of injury-time nearly took the roof off Old Trafford at the end of a dramatic 4-3 victory.
It is a semi-final though, and United are eager to debunk the myth that it means more to their opponents just because the Reds have enjoyed 17 such occasions since City reached the FA Cup final under John Bond.
"That is a popular argument," reflected Ferguson.
"But it doesn't matter how many semi-finals you have played in, they are occasions when you always want to do well. That is important."
It is why Ferguson will be spending a good deal of his time trying to get the team selection right.
Rio Ferdinand will not be considered despite edging closer to full fitness after three months out with a back injury.
Ryan Giggs is having a spell out of the team too, although Darren Fletcher is available after suspension and should be involved.
There is even a possibility Dimitar Berbatov could retain his place up front after Ferguson revealed he got it wrong on Saturday when he claimed his £30.75million record signing had suffered a recurrence of his knee injury during the win over Burnley, which hastened the Bulgarian's departure after he had opened the scoring.
"I thought Dimitar had got a knock on the knee," said Ferguson. "It turned out it was a dead leg and we are having a look at that it.
"I am hoping he will be all right but he is a doubt."
It will take Ferguson significantly less time to work out who will play in attack for City.
Carlos Tevez is certain to be involved, raising the possibility of a player who enjoyed such success in his two years at Old Trafford before leaving so acrimoniously, inflicting severe punishment on his former club.
Wisely, Ferguson is not seeking a confrontation, as he did with his summer claim that the South American's goalscoring record was patchy at best.
The response has been 16 so far this season, although for the United boss the issue is old news.
"What happens with him doesn't concern me," he said.
"You have to move on with life. Plenty of players have left here to go to other clubs.
"I wouldn't have thought it would affect him either. He always had a decent temperament."
The United boss is considering whether to add a bit of youth to his team in the form of Darron Gibson and the Da Silva twins Rafael and Fabio.
Having already absolved the younger members of his side from blame for the shock home FA Cup defeat by Leeds, Ferguson would have no qualms about putting them into such a high-octane encounter.
But it does seem the United boss intends to select a far stronger team than the one he originally intended when the draw was made last month.
"I have got to think about getting a mix in terms of the programme we have got and also the fact I have given young players a game in the past," he said.
"I will have a strongish team but there will be some young players as well."