Ferguson and United have already achieved the improbable. The treble in 1999 may seem routine in comparison to the feat of lifting five pieces of silverware in one season, but no club has pulled it off since and United remain the only English team to do it.
The quintuple would be football's equivalent of an earthquake that breaks magnitude nine on the Richter scale, but the early tremors are already being felt.
The Fifa Club World Cup is already in the bag and Spurs are threatening to offer as much resistance as a lace curtain in next week's Carling Cup final. Five points clear of the pack in the Premier League and with a favourable draw in the quarter-final of the FA Cup, is the Champions League the only trophy still legitimately up for grabs?
Jose Mourinho and Inter Milan will ensure that United are pushed to the limit in their Champions League last 16 encounter, but Ferguson's players are now embracing the challenge of rewriting history and Wayne Rooney, whose goalscoring return from a six-week hamstring lay-off against Fulham on Wednesday underlines United's ominous strength, admits that the quintuple is now up for grabs.
Rooney said: 'Personally, I want to win all the trophies. People talk about the Champions League and Premier League, but I've had my two biggest heartaches in football in the FA Cup [losing to Arsenal in the 2005 final and Chelsea in the 2007 final] and I want to make amends for that.
'The Carling Cup was the first major trophy I ever won and I want to win that again. If we can win any of these trophies, it will be a great boost for the club and we're delighted we are still in all the competitions.
'At the start of the season, the aim is to go as far as we can in all of them, so to be still be in all of them in February is fantastic. If we can win a few of them, it would be great for the club.
'We know the position we are in and it is obviously always nicer to be top of the league rather than chasing, which we have been for most of the season. But now we are a few points clear, we know what we have got to do and hopefully we will do it.'
One train of thought within the game is that United's Achilles heel could ultimately prove to be their domestic dominance. Just as in Scotland, where Celtic and Rangers are rarely tested sufficiently ahead of European fixtures, United could yet find themselves suffering from ring-rust in the San Siro next Tuesday. Nobody has laid a glove on Ferguson's full-strength team since Arsenal triumphed 2-1 at the Emirates on Nov 8.
With 13 league games left to play, only two of United's remaining six away games are against teams in the top 10 – Fulham and Wigan – while Liverpool, Arsenal, Aston Villa and Manchester City are all due at Old Trafford.
As a veteran of eight successful Premier League title campaigns, however, midfielder Paul Scholes has issued a note of caution and highlighted the lingering threat posed by Liverpool as virtually everybody outside of Old Trafford begins to deck the league trophy in red, white and black ribbons.
Scholes said: 'We have a five-point lead and that's a good one to have, but there's a long way to go yet and we still have 13 games left in the league.
'We've got Liverpool to come to Old Trafford as well, so they will still fancy their chances. They are still playing quite well, so I think it's still going to be tight.'
Wednesday's ruthless dismantling of Fulham suggests that United are in no mood to allow Liverpool or anybody else to get in the way of their march to glory, however.
That 3-0 victory was achieved without the likes of Ryan Giggs, Gary Neville, Wes Brown, Nani, Rafael da Silva and Darren Fletcher, but Fulham were simply brushed aside.
Fulham manager Roy Hodgson said: 'United are a very good team with a very good chance of winning the league. They play with great composure and, against us, their passing and movement was very good.
'On top of that, they have the individuals who, when the ball is in the final third, either wide or in central areas, can fashion goal chances and shots out of nothing at all. Whatever team Alex puts out will cause you problems.
'When we crossed the white line we simply found a Manchester United team that had too much in their locker.'