There is nothing quite like a frantic first Monday back at the office to finally snuff out a holiday. Amid the trill of telephones and faxes, thoughts of sandy shoes and suntan lotion fade quicker than you can say margarita, por favor. The importance of being business-like reasserts itself with alarming speed. It is a violation of the senses.

It took all of 11 and a half minutes for Manchester United's beachcombers to be reminded of these unpleasant facts at Old Trafford on Monday night. That was the moment Arsenal's Fredrik Ljungberg interrupted Jaap Stam's winter siesta, dispossessing the lumbering Dutchman with a secretary's efficiency before slotting the ball through the gaping legs of Mark Bosnich and into Alex Ferguson's in-tray. Hey, Alex, you've got mail, and it's not a postcard from Rio.

It was more like a letter of intent from Arsene Wenger, one that said that Arsenal, even without Tony Adams, Marc Overmars, Dennis Bergkamp, Nwankwo Kanu and Davor Suker, are still capable of chasing United into the final furlong of this Premiership season in May. A most necessary harassment it is too.

For had Wenger not employed his depleted resources so intelligently - had he not subdued the supply lines from Gary Neville and Denis Irwin to David Beckham and Ryan Giggs with Ray Parlour and Stephen Hughes's diligence; had he not surprised Stam and Mikael Silvestre with Ljungberg's versatility; had Roy Keane not been isolated by the immaculate brilliance of Patrick Vieira and Emmanuel Petit - then Arsenal may well have departed Manchester without even a sore point. And that would have had profound implications for everyone. Professor Wenger has done the neutral a service. Not forgetting Leeds United.

Because if Arsenal had succumbed, then Ferguson's decorated players would have woken to Manchester's misty morning one point behind Leeds with two games in hand. Those are against Middlesbrough at home on Saturday and away to Sheffield Wednesday next Wednesday. It has the feel of six points for United. Very nice.

Arsenal, meanwhile, would have been four points off Leeds and have yet to visit Elland Road. Even now Arsenal have played three matches more than the reigning champions, but they have sent out a message that they are contenders still.

That is undoubtedly a good thing. Take away Arsenal's Double season of 1997-98 when they won the league by a single point from United, and Ferguson's men would have won the last four Premierships. Then take away Blackburn Rovers' solitary point triumph in 1994-95 and United would have won all seven Premiership titles to date with an eighth looking likely. Those two slim points spread over three years made a big fat difference.

Or did they? Given that Andy Cole's misses at Upton Park on the final day of the '95 season were a contributory factor in Rovers' title and that Keane, as Parlour observed before Monday, was absent for most of Arsenal's Double season, United have exerted a stranglehold on the Premiership since its inception that would impress even Ibrox's monopoly men.

Hats can only be doffed in Ferguson's direction for his achievement. But, unlike Liverpool's equivalent and even greater omnipotence in the 1970s and 1980s, United's rise has had a financial correlation that is troubling. If and when they sign their new £50 million shirt sponsorship deal, their power will only grow stronger. To put the shirt contract in perspective, Newcastle United's annual turnover is £55 million. It is the second highest in England.

Economically, therefore, United are blitzing the competition. It is nearly inconceivable now that in the inaugural Premiership in 1992-93 a club the size of Norwich City came third. But they did. The idea of a similarly sized provincial club competing seriously again now seems as far-fetched as Stan Collymore's personality. Maybe that's why Leicester are interested in Stanley.

So the Arsenal and Leeds challenge to United is welcome. Over the next few weeks they may find help from Coventry City - Robbie Keane at Old Trafford - and Newcastle - Alan Shearer at St James' Park. After that come Leeds at Elland Road. That fixture was re-arranged hastily yesterday. Depending on whether Leeds progress in the FA Cup, it takes place on either Wednesday February 16th (8 p.m.) or Sunday 20th (11.30 a.m.). Dwight Yorke, who misses the Newcastle match because of international duty, could also miss Leeds.

Paul Scholes, scheduled to play for United's reserves at Everton last night, should be back by then. No doubt Teddy Sheringham will also be on his toes again, as will Denis Irwin against his first club. Both Sheringham and Irwin are expected to sign new contracts shortly and though Irwin has announced his international retirement and was substituted on Monday, Ferguson insists "he is still the best defender in the game. His two feet, his balance, his experience is invaluable. That bloody mob Oldham robbed me!"

Then, in the first week of March, United entertain Liverpool. They will already have begun their four consecutive midweek Champions League games by then and it was this Vieira referred to when he said: "They have so many important games in a short period of time, they can't win them all. They also have to deal with the pitch. It's new, and while it looks good, it's hard to play on. The championship is not finished yet."

While talking the elegant Vieira was greeted affectionately by David Beckham and his baby, Brooklyn, and the mutual respect between the players was obvious. Vieira then made flattering comments about Beckham. But, going through Beckham's mind as he engaged the 6ft 4in man from Senegal, must surely have been the realisation that Manchester United are back at work.