Alex Keble says the on-loan Barcelona enforcer must be at his best to combat the talents of Santi Cazorla on Saturday...
Considering the vastly differing fortunes of these two sides, Arsenal should extend their sequence of league victories to five and send West Ham deeper towards mid-table obscurity. If Sam Allardyce is to pull off a shock result at the Emirates Stadium, he will need to employ the same tactical model that was so effective in the 2-2 draw against Spurs last month.
In that match, Allardyce cleverly instructed his three central midfielders to sit compactly in front of the back four. With the vast majority of Spurs' attacks coming through the centre (where inverted wingers cut inside to join a deep-lying Harry Kane), Alex Song, Mark Noble, and Cheikhou Kouyate crowded them out.
Song made good contributions in central areas, helping to keep Kane quiet: note how often the England man lost aerial duals (orange triangles) and failed take-on attempts (orange stars).
The defensive contributions of these three – 10 tackles, 6 interceptions combined – will be needed again, with Arsenal similarly relying on attacks through the middle (32%, the highest proportion in the division).
This Stats Zone screen highlights Arsenal's narrowness in attack, and West Ham's central tackling at Spurs.
Although Alexis Sanchez dominated the headlines in the early part of the season, recognition of the tenacity and effortless class of Santi Cazorla has grown since the turn of the year.
It's testament to the Spaniard's work-rate that as well as contributing significantly to Arsenal's attacks (his 2.6 dribbles and 2.2 key passes per match is bettered only by Sanchez), Cazorla has also made more passes than any other Gunner this season.
It is no coincidence that Arsenal have failed to win any of the four league matches in which Cazorla hasn't started. With most teams operating with deep defensive lines to counter Arsenal's short-passing system, they often require the direct dribbling and ingenuity of Cazorla to break through compact lines of defence.
Cazorla is outstanding at both taking on players and controlling the game with his passing: both of these skills will be vital against a powerful West Ham midfield.
If Song and his fellow central midfielders show discipline in staying deep and narrow, they may nullify Mesut Ozil and Sanchez. Whether they can prevent Cazorla from dominating is another matter.