All has not gone to plan for Manchester United.
Whilst their early season form can perhaps be shrugged off as teething problems, the signing of Juan Mata - which came at the end of a run of five wins in six league games - was meant to herald a new beginning and a surge in their chances of qualification for next season's Champions League.
However two wins from their last six league games, combined with some discouraging performances, means that they head to the Emirates tonight in seventh position to face a team that can return to the top of the table with a win.
In order to get anything from the game, they are likely to have to abandon the tactics that saw them put in a staggering 81 crosses during Sunday's 2-2 draw with Fulham, in favour of a more intricate approach.
Key to this will be the relationship between Wayne Rooney and Juan Mata in the area behind lone striker Robin van Persie. An area that should be the side's main strength given the personnel available to them, comes up against an Arsenal defensive midfield that was brutally exposed by Liverpool at the weekend in what could prove the game's key battles.
Playing in the number 10 role behind the striker for much of the season, Rooney has created more chances than any other United player this season.
He has created 43 in 20 appearances, in addition to nine goals, and is likely to start behind Van Persie at the Emirates tonight.
Given his tendency to roam across the pitch, demonstrated on the heatmap above, it will fall to Arsenal's defensive midfielders to deal with Rooney rather than Laurent Koscielny and Per Mertesacker.
Defensive midfield was an area that was shown up in the opening 20 minutes of Arsenal's 5-1 defeat to Liverpool at Anfield on Saturday and the likely pairing of Jack Wilshere and Mikel Arteta will have to improve significantly on an opening period that saw them ship four goals in just 20 minutes.
Both Arteta and Wilshere are accomplished performers on the ball. At the attacking end of the pitch Wilshere's quick feet and short bursts forward make him one to watch in an attacking sense, whilst Arteta is key to setting Arsenal's attacking tempo.
However neither are the kind of midfielder to relish the defensive aspect of the game and if Manchester United can get on the front foot against Arteta and Wilshere, then Rooney and Mata could find some joy if they can attack the Arsenal pairing.
The Gunners are missing the injured Aaron Ramsey's energy in midfield areas at the moment. The comparison matrix above shows his ability to break up play through his tackling; with neither Wilshere nor Arteta coming out well from comparisons with Ramsey and their opposite number at Manchester United, Michael Carrick.
Against Liverpool, they lost the midfield battle. Liverpool attacked through the centre with pace and power as if the Arsenal midfield were not there, with over half of their created chances coming through the middle.
Whilst United don't have the raw pace of Liverpool's attacking players, they will be optimistic of being able to use the likes of Rooney and Mata to spark any counterattacks. A number of Liverpool's chances were created from deep areas on Saturday, as they went from back to front extremely quickly, and both Mata and Rooney have the ability to launch counter attacks through a long pass for the likes of Van Persie and Ashley Young.
This does, however, rely upon Mata being allowed to roam. If United are to exploit Arsenal's soft centre, then he will have to be allowed more freedom than he had against Fulham.
With Rooney playing in the centre, Mata has been forced to the right hand side to accommodate the England man. His performance against Stoke, despite the loss, showed that he can come inside and influence the game from that position, but he must be allowed to do so.
Against Fulham Mata's heat map shows his positioning was far wider than the Stoke game, meaning that he had less effect. To sign a player such as Mata and then play him on the right hand side with an instruction of staying wide and whipping balls severely lessens his impact, and he should be allowed to occupy positions similar to those that he did at Stoke, rather than against Fulham.
With attacking full backs and a genuine wideman on the left in Ashley Young, Mata and Rooney can be given license to combine centrally without any loss of width. Should they do so, then they can provide a creative hub and send out an ominous message to their rivals. In Van Persie United possess a deadly finisher, but he cannot finish without the service, making Rooney and Mata's contribution to tonight's game crucial.
The pair are yet to click, but have outshone Arsenal's creative duo of Mesut Ozil and Santi Cazorla in their impact this season. Mata has averaged an assist per game for United so far, albeit in just three games, whilst Rooney has a better goals, chances created and assist per minute record than both Ozil and Cazorla have this season.
Arsenal head into the game as favourites, but if their creative duo can click then United have a real chance of piling further misery onto a Gunners side that shipped five goals in their last fixture.