Since his arrival from Lorient in 2010, Koscielny has had his fair share of ups and downs at Arsenal.
He has hit patches of good form throughout his time at the club, and personally, I prefer him to Mertesacker at the heart of Arsenal’s defence.
However, he has been on the wrong end of several silly errors, the most notable of which were the horror miscommunication with Wojciech Szczesny that lost Arsenal the League Cup Final to Birmingham City, and a completely unnecessary rugby tackle in the penalty area on Edin Dzeko against Manchester City earlier this season that earned him a thoroughly deserved red card. Arsenal went on to lose 2-0, despite the penalty being saved.
He certainly has his qualities, though, being very quick for a centre-back, and being much more comfortable in possession than his German counterpart. And the player has claimed that despite his current lack of first-team action, he will not be looking to leave the club. He still has 4 years left on his contract after June, so any talk of his exit is likely to be purely speculation. Fans may welcome his commitment to stay at the club, but many feel that additional centre-back reinforcement is still required, due to the inconsistent form and injury-prone tendencies shown by pretty much the whole Arsenal back line, despite their obvious qualities. Still, keeping a decent player can only be a good thing for the club.