Since the frustrating encounter against Chelsea at the Emirates Stadium late last month, and his fateful sending off, Per Mertesacker has found himself on the sidelines. He has had to watch on as Arsenal kept two clean sheets in as many league games under the stewardship of a central defensive pairing of Laurent Koscielny and the German’s replacement, Gabriel. But should this be a long-term defensive alteration? Probably not.

It may seem harsh to already be insisting on reverting to the defensive pairing who have overseen Arsenal through a period of relative success for nearly three years, primarily because Gabriel has done nothing drastic to warrant replacing. Indeed, he has not yet made an error which has directly or indirectly led to a goal but the Brazilian does have his weaknesses. For instance, Gabriel’s proclivity to get caught goal-side has led to a couple of potentially perilous attacks from opposing players, most notably in the first half against Bournemouth last weekend.

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In addition to these occasional lapses in his positioning, Gabriel also does not appear particularly confident on the ball, yet has endeavoured to play out from the back. This became problematic on more than one occasion against Southampton — given the pace and tenacity of their forward players, they were able to catch Gabriel in possession as a result of this. Indeed, the fact that the 25-year-old is quicker than Mertesacker means nothing if he can’t keep the ball against attackers who are sharp enough on foot and in their mind to punish his ball skills. If, as James McNicholas of Gunnerblog suggested on this week’s Arsecast Extra, the Brazilian’s recent selection is an attempt to forge a coherent partnership with Koscielny before the visit of Neymar, Luis Suarez and Lionel Messi, then Gabriel will need to stay more composed on the ball or risk a torrid night against the Blaugrana triumvirate.

While we’re on the subject of coping with pace as an attacking threat, let’s turn our attention to Mertesacker. It has long been stipulated that his lack of speed is an alarming weakness and if you were to lazily half-watch the sequence of events leading to his sending off against the Blues, then you may well agree. However, this notion of pace being the be-all and end-all of defending against quick players has been forged by those who prefer poring over statistics on FIFA Ultimate Team to watching actual football. In fact, you could probably count on one hand the number of times in his Arsenal career that Mertesacker has been genuinely found out due to his slow and cumbersome nature. Pace is simply not an issue. If it was a problem, he wouldn’t be playing at this level, he probably wouldn’t still be at the north London club and he certainly wouldn’t have won over 100 international caps.

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On the contrary, Mertesacker is perhaps one of the more difficult Premier League defenders to play against given that what he lacks in physical speed, he more than makes up for in mental agility. He is rarely found wanting in a foot race because he is clever enough to steer clear of them and the German’s positioning and reading of the game is unparalleled throughout the squad, making him the perfect partner for the agile and athletic Koscielny.

In fact, his relationship with Koscielny is symptomatic of Mertesacker’s presence. As well as his partnership with the Frenchman, which has been essential to the skeletal structure of this Arsenal team in the last three seasons, he appears to have a great relationship with Petr Cech. Pictured numerous times doing their own novel dual-celebration, they appear to have found common ground in deriving the same pleasure from clean sheets as other players do from netting at the other end. This common ground extends beyond this, however – Cech and Mertesacker are the two bastions of palpable leadership and towering figures of authority in the dressing room. The sending off will have hurt the German, and he will be keen to make amends in the most rewarding way upon his return to captaincy.

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It is this leadership role that Arsenal will need most in the impending Premier League run-in. While having the nucleus of an able Premier League defender, Gabriel is still rather raw. He doesn’t exude the same assuredness and leadership as Mertesacker. And with the huge game against Leicester City now closing in, Arsenal need their giant German to play his role as the guardian of the Gunners’ Islington stronghold more than ever.