Why Mertesacker and Koscielny Is Arsenal's Best Centre-Back Partnership

Arsenal are a side desperately searching for defensive security. After two consecutive clean sheets against Everton and Watford, they have since conceded four goals in two games.

Poor defending has cost them four points in the last fortnight, and Arsene Wenger must now be considering a recall for Per Mertesacker.

Mertesacker has been an unused substitute in each of the last five games. The German was last named in the starting XI for the FA Cup quarter-final defeat to Watford. It seems he was made one of the scapegoats for that particular result, with Gabriel Paulista drafted in as his replacement.

It’s somewhat surprising to see Mertesacker on the sidelines. Not only has he worn the captain’s armband for most of this campaign, but his partnership with Laurent Koscielny has been one of the key components of the Arsenal team for several seasons now. At one stage, Koscielny and Mertesacker went for more than two years without suffering defeat when playing 90 minutes as a pair, per the Daily Mail's Sami Mokbel. 

As reported by the Sun's Mark Irwin, Mertesacker eulogised about the understanding he and the Frenchman had developed: 

We know each other much better now and we complement each other well.

Laurent is more mobile and I have more height.

It fits together perfectly because these days centre-backs are more than just tall defenders whose only job is to head away the long balls.

Laurent is one of the quickest players I’ve ever partnered and he anticipates things so well.

We both feed off each other’s strengths and that is the main key to our success this season.

Mertesacker’s positional awareness and Koscielny’s speed helped to cancel out each other's respective weaknesses and strengthened the partnership as a whole. Even as recently as October, ahead of a UEFA Champions League tie against Bayern Munich, Wenger said he believed the duo represented Arsenal’s best chance of stopping the in-form Robert Lewandowksi, according to the Sun's Irwin:

We have to be shrewd with him because inside the box he is outstanding. His technique, his movement and his finishing is top class.

That’s where we will need all the experience of defenders Per Mertesacker and Laurent Koscielny to deal with that.

We want to defend well, attack well and score the first goal. That is massively important.

Mertesacker and Koscielny kept Lewandowski relatively quiet that night as the Gunners ground out a clean sheet and a 2-0 win. However, the German’s performances dipped significantly after that point. At 31, there have been indications age is beginning to catch up with him. 

However, Gabriel has not convinced as his replacement. The Brazilian is far quicker than Mertesacker, but he is prone to being somewhat impetuous. He also has an aggressive streak that can sometimes land him in trouble.

In the longer term, Arsenal do need a new centre-back. When the summer transfer window opens, Wenger should be on the lookout for someone who can be Koscielny’s regular partner throughout 2016/17. 

For now, though, Mertesacker remains the best bet. Arsenal are rocking, but the German has the experience required to help steady the ship. At the very least, he and Koscielny have an understanding honed by years of playing together. That could be enough to help Arsenal make it through until May.

James McNicholas is Bleacher Report's lead Arsenal correspondent and is following the club from a London base throughout 2015/16. Follow him on Twitter here.