Unai Emery has a plan to address his centre-back shortage when Arsenal travel to Southampton on Sunday.
Captain Laurent Koscielny made his first appearance of the season in Thursday's 1-0 win over Qarabag in the Europa League.
The 33-year-old suffered a ruptured Achilles in May that ruled him out of France's triumphant World Cup campaign.
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Koscielny completed 72 minutes alongside Sokratis Papastathopoulos but the luxury of deploying two specialists at the heart of his defence is not one Emery will enjoy at St Mary's.
Sokratis is suspended after collecting a fifth booking in 10 Premier League appearances against Huddersfield Town last weekend, while Shkodran Mustafi is recovering from a hamstring strain and Rob Holding's season is over following cruciate knee ligament surgery.