Shokdran Mustafi, Rob Holding, Callum Chambers, Dinos Mavropanos and Sokratis are Arsenal's current options at center back, but there's no doubt Koscielny would have been a starter alongside Sokratis this season.
"We are very disappointed by Laurent's actions, which are against our clear instructions." the statement read on Arsenal's official website.
Koscielny did not feature for the Gunners until December last season, spending seven months on the sidelines overcoming a serious Achilles injury suffered in Europa League semi-final defeat to Atletico Madrid last May.
Sky Sports News understands Koscielny wants to return to France and has asked Arsenal to release him from his contract, which has one year remaining.
The defender reportedly has interest from Ligue 1 sides Bordeaux, Rennes and Lyon (BBC Sport), and is seemingly trying to force his exit from the Emirates Stadium.
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They'll "twirl his/her index finger toward the referees" to signal for the challenge. So I think at the end of the day, it's positive for the league".
He may conclude that there is no room for individuals who have not demonstrated total commitment and seek a replacement.
What a mess. Koscielny hasn't conducted himself well here, and Arsenal putting this out in the open has escalated the seriousness of the situation. And while they recognise the service he has given they have no intention of letting him leave for nothing while he still has time left on his existing deal.
Even more problematic is the fact that Koscielny would nearly certainly have been a starter next term if defensive reinforcements were not made. Only time will tell in that regard, but this incident is the last thing that Arsenal needed.
Arsenal released a surprise statement on Thursday revealing their skipper has gone against club orders and stayed behind while the rest of the squad have flown out to the USA.
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