The Gunners manager revealed earlier this week that experienced centre-half Per Mertesacker is set to be sidelined for a 'number of months' with a knee injury.
While fellow centre-backs Gabriel (illness) and Laurent Koscielny (holiday) were also left behind as the squad flew to the United States for two pre-season fixtures.
Calum Chambers, 21, is currently the most experienced central defender on the tour, with new signing Rob Holding, 20, also likely to feature in both games.
Wenger admitted Mertesacker's injury will force him back into the market for further defensive recruits, but midfielder Coquelin believes he's ready to take on the challenge.
When the club's official Snapchat account asked what he had been focusing on in training, the 25-year old replied: "I've been playing centre-back and I've been bossing it."
Spanish website Plaza Deportiva reported yesterday that Arsenal have asked Valencia over the availability of Mertesacker's compatriot Shkodran Mustafi, who has a £42million release clause.