Arsenal-Tottenham derby 'the most crucial' in Arsene Wenger's reign

On the face of it, there is no reason why Tottenham's trip to Arsenal on Sunday should carry more significance than previous north London derbies.

Two fierce local rivals, three keenly contested Premier League points and one much-coveted set of bragging rights - so far, so familiar.

But scratch beneath the surface and an entirely different picture emerges.

"This is the most important derby in Arsene Wenger's 16 years as Arsenal manager," former Gunners right-back Lee Dixon tells BBC Sport.

"It comes at a very poignant time in the club's history."

Out of contention for every domestic trophy and facing likely Champions League elimination, Arsenal are staring at a seventh consecutive trophy-less season.

Defeat by Tottenham, who have never finished above their neighbours during Wenger's tenure, would leave the Gunners 13 points behind third-placed Spurs in the Premier League with 12 games remaining.

Unless Arsenal then won a probable four-way scrap with Chelsea, Newcastle and Liverpool for fourth place, their 15-year run in the Champions League would be over.

"If they don't get Champions League football next season it's going to be a nightmare," says ex-Arsenal midfielder Emmanuel Petit.

"To get back to where they were, Arsenal need to sign big players in the summer and you can't do that if you don't play Champions League."

Following devastating defeats by AC Milan in their last two matches, Arsenal will be desperate to reignite their season against Spurs.

It is a league fixture that Wenger lost only once in his first 14 years at the club, but all evidence suggests the tide is turning.

Arsenal have won just one of their last seven top-flight meetings and go into the game below Tottenham in the table for only the fourth time in Wenger's 32 derbies.

"Spurs are a better team than Arsenal," Petit admits, while Dixon adds: "There has definitely been a gradual shift of power over the last few seasons."

Football analyst and author Alex Fynn wrote a book in 2000 entitled The Great Divide, which sought to explain Arsenal's dominance over Tottenham.

"Certainly there is no great divide now," says Fynn. "If anything, it may be role reversal."

This has not gone down well with the crowd at Emirates Stadium, where rumblings of discontent have been audible for some time.

Tim Payton, spokesman for the Arsenal Supporters Trust (AST), describes it a "a culture shock, a wake-up call for Arsenal fans who have been used to enjoying St Totteringham's Day".

That is the name Arsenal followers jokingly give to the date each season when Spurs cannot mathematically finish above Arsenal.

Unfortunately for them, that holiday looks like it will not be celebrated in 2012 and many of those fans are questioning how it has come to this.

Wenger lifted seven trophies in his first nine years at Arsenal, but now looks set to endure the longest barren spell of any manager in the club's history.

"Wenger needed a challenge from his backroom staff and the board," Fynn argues. "This is the most significant problem he has failed to deal with.

"The other major clubs have arguably had better backroom staff and refreshed them on several occasions. Just look at Manchester United.

"Wenger has never had this and, as other clubs have moved on, Arsenal have stood still and maybe even gone backwards.

"Why has he not surrounded himself with men of quality? What on earth is [retired former Arsenal captain] Patrick Vieira doing at Manchester City?"

Fynn also blames the 2007 departure of chief executive David Dein, who remains Wenger's best friend, for Arsenal slipping behind their rivals in the transfer market.

This is one of many areas in which Tottenham have excelled since chairman Daniel Levy appointed Harry Redknapp as manager in 2008.

"Spurs were branded a team without ambition for almost a decade," Petit explains. "But in the last two years they have signed so many good players and big characters that this team seems far more competitive than Arsenal.

"All of a sudden the politics changed and they started to spend a lot of money. Big wages, bringing in many international players with big experience, big characters - mixing the likes of Rafael van der Vaart and Emmanuel Adebayor with very good players already in the team like Gareth Bale, Aaron Lennon, Jermain Defoe.

"Now the quality is there and they have the mentality too. It will be very interesting to see how Arsenal react to this, especially at home. It's a massive test after what's happened during the last week."

Dixon adds: "Going into a north London derby, as fans you'll read lots of stuff. As players you put that all out of the way, you forget it, because it is ultimately about what happens on the day.

"The thing to pay more attention to is recent results and Arsenal's form is poor.

"That in itself is demoralising. But when I was at the club, if we ever had a bad series of results the next game you want to be a big one because it gets your mind focused on what's coming rather than feeling sorry for yourself.

"And there's no bigger one than the north London derby at this stage of the season with so much at stake. So roll your sleeves up and get stuck in."

The AST estimates that missing out on the Champions League could cost Arsenal £45m and that is why Payton thinks Sunday is "much more than a north London derby".

Victory would bring fresh hope but, for Arsenal and Wenger, defeat does not bear thinking about.

"That would be the third body shot in quick succession," says Fynn. "It may be the knockout blow."