Arsene Wenger looked like he needed to go to bed with an extra blanket, a hot drink, and as many flu remedies as he could stomach. It hardly seemed like the ideal state of being for a man preparing for a date that has virtually jumped out of the calendar in recent weeks, such is its shuddering importance.

The more Arsenal have stuttered over the winter, the more the pressure on the upcoming North London derby has mounted. Arsenal have had wobbles before during Wenger's long reign at the club, but they have always had the safety net that even in times of trouble, Tottenham were invariably worse off. The fact that their oldest foe is currently in a position to taunt them somehow magnifies all the concerns swirling around Arsenal. Frankly, though, they have enough to worry about all by themselves.

Eight defeats in their last 18 games is a rotten run by any standards. During that spell they slipped out of contention for silverware. Players that could usually be relied upon look shorn of form and confidence.

The saving grace (for now) is that despite all their unimpressive results they are still in position to seize fourth place in the Premier League , and with it entry to the Champions League next season. They clearly need to shake their way out of their malaise to hold onto that spot. They have one challenge left, and they have to rise to it. There could be no better place to start than against their historic rivals.

Wenger was on the defensive ahead of Sunday's showdown. Any queries about whether Tottenham were faring well, or what he thought of Harry Redknapp, or why he didn't once buy Gareth Bale, either provoked a swift change of subject or a gentle reminder about who has been top dog in these parts for as long as he has been the manager. "The only thing you can say is, in the last 15 years Spurs have finished behind Arsenal," he noted crisply.

So quickly can the winds turn in football. Arsenal's trepidation as they approach the derby is so raw it has all but obliterated all the superiority the years of supremacy created. For a decade Wenger barely knew what it felt like to a lose Premier League game against the neighbors. In his first 13 seasons in English football, he lost only once, at White Hart Lane, and never at home. Arsenal's dominance was brutal.

Tellingly, while Wenger went about his work, down the road at Tottenham they changed management more than a dozen times. They attempted to replicate the Arsenal model by selecting foreign managers with interesting reputations - Christian Gross, Jacques Santini, Martin Jol, Juande Ramos. They hired an ex-Arsenal man in George Graham. They went for a Spurs legend in Glenn Hoddle. They returned time and again to stalwart David Pleat to steady the ship. Nothing worked. Until, that is, in 2008 they invited Harry Redknapp to north London and have never looked back.

It was in Redknapp's first season that there was the first evidence that the sands were shifting. Arsenal and Tottenham drew 4-4 at the Emirates, but all the celebrating took place in the visitors section as Wenger's team, who had been showboating as they led 4-2 with a couple of minutes remaining, found their good cheer punctured by two late Tottenham goals. It was a sign of the status quo that a draw made Spurs euphoric and Arsenal furious, but beneath the statistics everybody inside the stadium felt something had changed in the relationship.

Arsenal know that defeat will have damaging consequences. Even before the game, questions are being asked about the caliber of the players, the decision-making and powers of motivation of the manager, and the business model presented by the owners. An unhappy outcome this weekend and those questions will turn into an ugly clamor.

It is still extraordinary for Tottenham to go into a derby at the Emirates as favorites. Their consistent, confident football merits that, especially coming at a time when Arsenal are desperately seeking a boost, having been flattened in successive cup games at Sunderland and AC Milan. "To feel sorry for ourselves would be criminal," said Wenger. "Let's go for it."

They must. They simply cannot contemplate anything else.