Normally a European match is noticeable because of the clash of styles involved. Think Inter Milan’s immovable object against Barcelona’s irresistible force. Similarly, Tottenham have stunned Europe by using traditional English wingers and an old-fashioned target man. In the Europa League, Napoli played a three man backline against teams used to a more traditional back four. Arsenal against Barcelona is different because they could almost be the same team. It’s almost as if Wenger looks upon Guardiola’s team as the ultimate realization of his Arsenal, for every year they seem to incorporate a little bit more of Barcelona’s philosophy.

The sides have nominally different formations, a loose 4-3-3 for Barcelona while Wenger has shifted to 4-2-3-1 in recent weeks, but both managers have incorporated fluidity into their shapes. Messi is a false nine who links well with Dani Alves, a right back that plays very high up the pitch, and Sergio Busquets drops down to cover for him. For Arsenal, Nasri is nominally stationed out wide, but often moves into the middle to link with Fabregas, and Van Persie also often drops deep to pick up the ball. Song and Wilshere have taken turns to shield the back four while simultaneously spreading the ball from deep. This season Wenger has also influenced a more cohesive, Barcelona-esque, pressing philosophy on his club, they do it more, and they do it better than before. The back line stays high up the field like their Catalan counterparts and their fullbacks provide width (however, compared to the myriad offensive weapons in Arsenal’s front six opponents have taken to playing very narrow and letting Sagna and Clichy bombard the box with crosses, it’s the lesser of two evils).

So, the two clubs play a similar style, and Barcelona have the better starting 11 (surely even Arsenal fans would agree with this). How then, do Arsenal win? After all, in recent memory Inter Milan and newly promoted Hércules haven’t matched Barcelona pass for pass, they’ve played a deep line, kept their shape and looked to hit on the break. Liverpool (less than four years ago, blimey) memorably went to Camp Nou and stood toe to toe with Barcelona, winning 2-1 but that was a different team, coming towards the end of the Rijkaard years. If Arsenal play defensively they’ll be crushed, they’re not used to it, and their back line isn’t good enough. Two years ago Koscielny was playing in Ligue 2, to expect him to be able to cope with David Villa and Lionel Messi is madness.

First of all Arsenal need to hope that Thomas Vermaelen is fit by February, because without a good ball-playing defender Arsenal will be eaten alive. Barcelona press relentlessly, and Arsenal’s style doesn’t lend itself to long punts down the pitch. Vermaelen is good enough to play the ball out of defense and start moves. Similarly, Wenger has to get Van Persie firing on all cylinders by the time this match comes around. He showed signs against Manchester City of being Arsenal’s version of David Villa, someone who can link well with the attacking players around him while being a focal point the offense can run through. But he still looks rusty and inconsistent after his return from injury.

Theo Walcott also needs to play, last year when these two sides met he made the difference at the Emirates. If he plays on the right where Wenger has kept him recently his tracking back qualities will be helpful against David Villa. His lack of defensive aptitude is also the reason Arshavin should stay on the bench. Wenger could take a gamble and play him as an inverted winger on the left, because most of Barcelona’s threat this season has been from Dani Alves marauding forward, sometimes stationed so high up the pitch he’s like an additional midfielder. Putting Walcott on his side would pin him back and force Pedro to come and help out. Either way Walcott’s pace should be the key against Barcelona’s high line.

What it comes down to is that both teams like to play the same way, keep possession and pass through the opponents defense. Arsenal have more depth in attacking options on the bench, but Barcelona have the better first team. Arsenal might have to go with a more direct approach in playing balls over the top for Walcott and Van Persie to run onto, something they’re not entirely used to. But given their relatively weak back line, Arsenal need to give themselves chances to score to stay in the contest.