Alex Ferguson says that he has been arguing for it for 25 years without anyone taking any notice; he certainly has been advocating it for the past three weeks or so and people, particularly Arsene Wenger, have been listening this time. Tonight at Old Trafford (live on Sky Sports 1, 8.0) we shall see just how significant a winter break is when Manchester United, without a domestic fixture since going to Sunderland on December 28th, face a depleted Arsenal side five days after they were involved in a two-hour FA Cup tie with Leicester City at Filbert Street.

With United and Arsenal level on 43 points, but with United having played three games less, a home win this evening would virtually signal the end of the Arsenal title challenge. That may sound premature given roughly 40 per cent of the season remains, but when it is remembered that two of United's matches in hand are at home to Middlesbrough on Saturday - an FA Cup weekend - and then away to Sheffield Wednesday, it is understandable that Wenger insists his team must not lose tonight.

Were that to happen and were United's players to be conspicuously fresh after their sunny Brazilian sojourn, then Wenger's already public resentment about United's withdrawal from the FA Cup and the benefits of their rest in Rio could boil over. He will say that United have been seen to have an unfair advantage.

Arsenal's task would be difficult enough without injuries or suspensions. But to approach such a vital contest with only one recognised attacker - Thierry Henry, and he is hardly a classic centre-forward - and without Dennis Bergkamp, Nwankwo Kanu, and Davor Suker and you start to appreciate the challenge facing Arsenal. Considering Suker's glaring aberrations in front of goal at Filbert Street, he could have done with the chance to repair damage, while for Kanu it would have presented him with the opportunity to remind people of his glorious debut in the corresponding fixture last season, also in February. It ended 1-1 but following his £4.5 million move from Inter Milan, the Nigerian put on a bewitching display of footwork and set up Arsenal's goal for Nicolas Anelka. How Wenger could be doing with either of those names on his teamsheet.

In differing circumstances that dearth of forwards would have led to Graham Barrett, once of the Kilnamanagh Boys' Club in Dublin, being awarded his full debut. But it seems that the 18year-old, as he was at Leicester, will be a substitute even if Liam Brady said on Friday: "If he plays, I'm sure he'll cope with the occasion. Technically he can do the job and he's got enough pace."

However, desperate not to lose, Wenger is set to play five across midfield with Henry a lone striker, and Frederik Ljungberg is favourite to start ahead of Barrett. The Swede has experience on his side and was the scorer at Highbury in August.

"It is certainly not my habit to let my team play for a draw," said Wenger. "But at the moment I am not sure whether we have another option." Wenger, remember, called Martin O'Neill's tactics "passive" last Wednesday. "But if I am forced to play with five men in midfield it may not be a bad thing because that is where the game will be won or lost."

United, having defeated Arsenal once this season at Highbury, begin as clear favourites even though Ferguson said: "We may be stronger in terms of team shape and so on this time, but you've still got to work hard to win these types of games. Most of his Wenger's players have seen it all and done it all. They are always going to be formidable whatever their final team."

Ferguson also cautioned against complacency and pointed to Middlesbrough's ring-rustiness after their three-week break. It is near unthinkable that Ferguson would let his players re-start in the same condition. Jaap Stam, for example, lost half a stone over the course of the two games he played in Brazil but he has returned fresh he said. The benefits of a winter rest are about to be put to the test. It is a shame that a match that should have been one of the highlights of the season is turning into something of a referendum.