It's been a long time since this fixture was played at a stage when Arsenal were ahead of Manchester United on the table -- five years, to be exact, when in November 2008 Samir Nasri terrorised Gary Neville and scored a double to secure a fine 2-1 win. That took Arsenal head off their title rivals, although they memorably faded in the second half of the season at which point United regained the supremacy. It was the first evidence in the theory that Arsenal can't handle the pressure of a thirty-game campaign. Wayne Rooney might still doubt the Gunners' credentials over the course of a season, but there's little doubt Arsenal are in a fine run of form at the moment, exemplified by the midweek win over Borussia Dortmund.
With Jack Wilshere remaining on an extensive injury list that also features Lukas Podolski, Alex Oxlade-Chamberlain and Theo Walcott amongst others, it's feasible that Wenger could name an unchanged side for the third successive match. Although Walcott is rated a chance to make his comeback in this match, it seems more likely Wenger will keep with his triple playmaker threat playing in behind Olivier Giroud -- the understanding and fluency of attacks between the attacking quartet, supported by deep runs from Aaron Ramsey and the full-backs, has been a highly impressive feature of their recent success.
Much, therefore, hinges on David Moyes' selection. He is a reactive manager, and often takes a cautious approach to big games. It's worth remembering that Alex Ferguson sometimes did as well, and it won't be unusual nor surprising if United stand off and instead play on the counter-attack. Many of United's attacks will flow down the flanks, and in particular, the left, where Shinji Kagawa's drifts inside midweek against Real Sociedad opened up lots of room for Patrice Evra to storm forward on the overlap.
Moyes will be concerned about Bakary Sagna's attacking threat, though, the Frenchman having created Ramsey's goal against Dortmund and Santi Cazorla's against Liverpool with his delivery from the right-hand side. Therefore, a more solid, disciplined player, like Danny Welbeck or Tom Cleverley, might be selected to help protect Evra, although there is also the possibility of the exciting Adnan Januzaj, whose quick acceleration and excellent first touch under pressure is useful for creating space.
The youngster also tends to drift inside, and regardless of who plays ahead of him, Evra will still get forward, even if just to send in lofted crosses from deep positions for Rooney and Robin Van Persie. This will be especially important in the absence of Rafael - Chris Smalling is a capable defensively, but can't replicate the Brazilian's powerful forward runs. Moyes will have noticed Santi Cazorla's lax tracking against Borussia Dortmund, and will be disappointed Rafael is unavailable to take advantage of the likely freedom down that side.
Moyes' other area of concern will be in central midfield. Michael Carrick is an injury doubt and Marouane Fellaini's troubles settling in at United were exacerbated by his red card midweek. Without even considering Moyes' likely desire to play with a very solid, holding duo to counter Arsenal's quick passing and overload of playmakers between the lines, it's possible that his only options could be two of Phil Jones, Cleverley or Ryan Giggs, who started in central midfield in the Champions League.
Yet there are questions about how many consecutive games the United veteran can play and although the Jones-Cleverley partnership fared decently last Saturday against Fulham, Moyes will be concerned about both players' tendency to be drawn towards the play and subsequently dragged out of position. Furthermore, Cleverley tends to perform well when United have the momentum, and with Arsenal likely to retain possession in advanced areas and mix the tempo of their passing, he might struggle.