An even first half, defined by United's diligence and a lack of cohesion through the Arsenal midfield, ended with a Gabriel Martinelli goal that would change the tactical pattern of the match. From here the visitors began to drop deeper, opening up pockets on the wings for Arsenal's individual quality to shine through, before formation switches from Chris Wilder swung momentum back.
Here's our five-point tactical review of the match from the Emirates Stadium:
1) Arsenal's individual quality makes up for lack of cohesion through the middle
There was a lot about Arsenal's performance that mimicked some of the better days under Unai Emery, in that attacks came with individualistic lurches towards goal rather than carefully constructed passing moves that pulled the opposition out of shape. After the early signs of automatisms against Man Utd and Crystal Palace, it was something of a step backwards today.
That's partly thanks to Sheffield United's compactness and hard work off the ball, but nevertheless the Gunners struggled to get support to Alexandre Lacazette while both Gabriel Martinelli and Nicolas Pepe appeared disconnected from the midfield. Direct dribbling down the flanks was Arsenal's only real source of attack, with bursts of quality from Mesut Ozil and an outstanding display from left-back Bukayo Saka certainly helping.
Arteta will want Arsenal to be more compressed and for the midfield to play with greater verticality and tempo; Granit Xhaka seemed hesitant, for example, meaning Lucas Torreira couldn't get into a fluent rhythm with Ozil and the front three. Much work lies ahead.
Note how infrequently Arsenal made passes in the number ten zone
2) Sheff Utd show ruthless organisation & look to bully Arsenal in the air
Wilder's side, for the first half at least, held Arsenal at arm's length by refusing to drop back. In a 3-5-2, their defenders sat ten yards inside their own half and dared Arsenal to break them down. Holding down the middle of the pitch with so many bodies, while not pressing the ball until it entered this zone, meant Arsenal were crowded out.
Arteta should have instructed his players to play longer passes over the top, especially given that Pepe's early chance came from Alexandre Lacazette dropping off and playing a blind through ball as the young right winger span in behind. Instead, Torreira and Xhaka were blocked by that superbly diligent United midfield.
In attack, United's main method was to launch aerial balls towards Olly McBurnie or get Enda Stevens in possession to attempt high crosses. Wilder knew the best way to intimidate Arsenal was to test their physicality, and with a flurry of headed chances in the first half it almost worked.
3) But Arsenal dominate flanks once Sheff Utd begin to drop off
Then again, this match really came alive once Arsenal took the lead – and they did so because of a change in tactical pattern that remained for much of the contest. United just couldn't keep up that high line, and as they started to drop big gaps emerged on either flank. That will happen when a 3-5-2 becomes a 5-3-2, creating inviting patches of grass in front of the deep-lying wing-backs.
Pepe and Martinelli enjoyed roaming down the wings, leading directly to the opener and the majority of Arsenal's second-half chances. Saka's overlapping on the left also played a vital part in a surge of attacking quality from the hosts after the break. However, once again this felt more to do with Sheff Utd's problematic shape and individual work from the trickier Arsenal attackers, rather than a sign of a cohesive or communicative Arsenal team.
It was during this period of the match that Ozil was at his best, ghosting into the channels to support Martinelli and Pepe. The German recorded four key passes, his most since Arteta's first game in charge at Bournemouth.
4) Wilder gets his formation switch right – at the second attempt
But there was to be one final twist, or rather two. First, Wilder brought Callum Robinson on for Josh Lundstram and the attacking midfielder played just behind the strikers in a 3-4-1-2. In short, it didn't work. Losing a body in the middle meant suddenly Arsenal could dominate the midfield, leading to faster breakaways and a stretched, end-to-end contest that clearly favoured the quicker side.
But credit to Wilder for having the humility to change formation nine minutes later, scrapping the plan that had put Arsenal firmly in control. Muhamed Besic came on for defender Chris Basham and United moved to a diamond 4-4-2, and although it initially looked like such a narrow formation would further assist the Arsenal wingers Wilder's decision was vindicated.
Within seven minutes United equalised after Besic broke forward and fed Robinson, still in the number ten role, to cross to the far post for John Fleck to score. The interplay between the United midfielders was a direct consequence of the manager bunching four midfielders close together.
For the final few minutes Wilder changed again, to a defensive flat 4-4-2 with Robinson moved to the left wing.
5) Arteta's side lack guile in the final third
The biggest takeaway from this game is that Arsenal need more subtle playmakers in the team. Lacazette once again showed that he doesn't have enough quality outside the penalty area to sew things together, while Pepe and Martinelli are too direct to consistently play together in this team. Ozil, blowing hot and cold, can't be expected to do all the creative work.
A priority for the summer should be to find an inside forward with guile; someone who can cut infield to link with a number ten and help Arsenal sustain territorial pressure for longer periods. They remain guilty of fading in and out, of looking a little lost when Ozil isn't showing for the ball. There is a good reason why so few elite clubs play with out-and-out wingers on both flanks.
- Graphics via Whoscored.com