Styles is in fashion

There was more controversy earlier in the campaign when Styles wrongly penalised Chelsea's Didier Drogba for diving, a decision that referees' chief Keith Hackett attributed to "poor positioning".

Of course, Styles is not the only official to make crucial mistakes this season, but some of his displays do cast doubt on the assertion he made three years ago that "the FA will appoint the top-performing eligible referee to do the final".

The word "eligible" is key. The FA stipulate that a referee may officiate at only one FA Cup Final. Thus Graham Poll, who oversaw the 2000 FA Cup Final and was widely praised for the manner with which he handled United and Arsenal's last meeting in February, is prevented from taking charge of Saturday's showpiece event.

In short, the biggest game in the domestic calendar does not, necessarily, get the best referee.

Styles, unlike Poll, has never refereed a United-Arsenal match. Previous clashes between the two teams have been notoriously ill-disciplined, and with so much at stake on Saturday - it is the last chance for either club to take home any silverware this season - there is every reason to believe that tempers might flare again.

It is that scenario, combined with Styles's heavy-handed approach - he has dismissed 57 players in the last five seasons - which has prompted fears that this year's final could end up being remembered for the wrong reasons.

Styles, however, will not share that apprehension. The successful businessman, who drives a silver Mercedes complete with personalised numberplate, will be eager to enjoy an occasion that might never have happened but for a conversation on the boundary at Waterlooville Cricket Club two decades ago.

Mick Pierce, a long-standing friend who was a linesman in the 1988 FA Cup Final between Liverpool and Wimbledon, said: "It was one of those scenarios where you are standing on the outfield and I said: "Why don't you take up refereeing Rob - because you're not any good as a cricketer?"

Styles immediately took Pierce's advice. In 1987 he completed a referee's course in his home-town of Portsmouth and, after cutting his teeth in the amateur leagues on the south coast, took charge of his first Premiership fixture 13 years later. and he has, according to Pierce, lost the arrogant edge that was a characteristic of his early years.

"To be a referee, more than anything you need confidence, though I think that Rob was overconfident in his early days," said Pierce. "He could be a bit OTT - sometimes you can believe in yourself a bit too much - but he's pulled back since then and got rid of all the rough edges. I have to say he's turned into a very good referee."

Styles will hope to prove that is the case at the Millennium Stadium on Saturday, but how will he react if Patrick Vieira clatters into Roy Keane only seconds after kick-off ?

"If there is a reckless tackle, whether it be in the 2nd, 34th or 90th minute then you have to caution it," said Dunn. "The fact it's Arsenal and Manchester United would have no bearing on that. If you start straying away from the laws of the game you run into problems and risk being labelled inconsistent."

Pierce, like Dunn, believes the history of trouble between United and Arsenal is in danger of being over-hyped. He said: "It might just turn out to be great game of football. But, if it's not, Rob will sort out what he's got to sort out. If the tempo of the game rises, he will rise with it. I have total confidence that he will do a great job and make his home of Portsmouth proud."

Styles, as with many referees, has his critics among managers, though he has endeared himself to others - including Chris Coleman and Iain Dowie - by ringing to apologise for decisions which he later realised were wrong.

However, you can't help thinking that an apologetic phone call to Arsene Wenger or Sir Alex Ferguson next Monday morning would not be received quite so well.