AT the heart of every quality team is a quality goalkeeper.
United, after winning the championship in 1967, suffered years of humiliation as they failed time and again to take the elusive title.
There were many reasons why they failed, but it is significant that, during most of the period from 1967 to their next championship success, in 1993, they did not have an outstanding goalkeeper.
After the early 70s United moved from the era of Alex Stepney to a hazardous experiment featuring the hapless Irishman Paddy Roche, and the likes of Chris Turner, Gary Bailey and Scotsman Jim Leighton.
Then, in August, 1991, manager Alex Ferguson paid the Danish outfit Brondby GBP550,000 for Peter Schmeichel, and played him 40 times in the 91-92 season.
A new era had begun. Not only did United have a goalkeeper of class, there were trophies on the way.
No one can say how many points a goalkeeper saves a team each season - although many try - but there is no doubt Schmeichel performs as important a role as any other United player.
Schmeichel concedes a goal every 113 minutes. Bailey conceded one every 97 minutes and Stepney one every 73. Statistics don't tell the whole story, but you get the idea.
The media highlighted Eric Cantona as the man whose goals earned United the championship in 1996, but Schmeichel's brilliant goalkeeping during the same period, especially towards the end of the campaign, was valued just as highly by Ferguson.
Schmeichel is a big, imposing figure with a nose that sometimes seems to shine as brightly as the shirts of the players in front of him.
The United fans love him. In the final game of last season, against West Ham, they urged Ferguson to allow the 'keeper to go forward.
Ferguson ignored the pleas, although he is not always that reluctant . . . Schmeichel managed to get on the scoresheet with a header against Rotor Volgograd in a European tie.
Schmeichel began charging upfield during emergencies when he was playing for a Danish side called Hvidovre. In one game he scored to earn Hvidovre a point which ensured they escaped relegation.
But Ferguson bought him for his work between the posts and that is where he excels.
Probably the best example of his ability came in a stunning save against Rapid Vienna last season. A downward header seemed destined to cross the line, but Schmeichel somehow managed to fling his huge frame down and palm the ball aside.
An official United video asks the buyer if it was the best save ever made.
Inevitably it has been compared to the save England's Gordon Banks made from Pele in the 1970 World Cup.
Schmeichel himself, in an interview with the magazine Total Sport, believes Banks' effort tops his own.
'Pele's header was powerful, the bounce of the ball was awkward, it was coming back up off the ground and Banks still managed to get a hand to it. Plus he had to move a long way.
'No, his was better,' he admitted.
There wasn't a world of difference between the saves, only the people who made them.
Banks, quiet, unassuming and brilliant. Schmeichel, a one-man shouting show on the pitch, but also brilliant.