Mavropanos joined the club from PAS Giannina for a small fee of £1.9 million in January 2018, but has failed to make the desired impact and could be facing the axe.
He has managed seven appearances in nearly two and a half years at the club, forcing Emery to consider the Greek defender’s ability to hold down a place in the Gunners backline.
The Spaniard has been dealt a huge blow with skipper Laurent Koscielny refusing to travel with the team on their pre-season tour of the United States.
Koscielny, 33, wants to leave the club and the Frenchman has been linked with a return home after several Ligue 1 sides have reportedly shown an interest.
His actions have disappointed the Gunners, who have slapped a £10 million price tag on their captain with under a month remaining in the transfer window.
Despite appearing to have fallen out of favour, Mavropanos has travelled to the States but Emery is reportedly unconvinced about his ability to fight for a spot in the first team.
This means Mustafi could remain with the club and become an integral part of Emery’s defence alongside Sokratis Papastathopoulos , with the Gunners hoping that Rob Holding recovers well from the cruciate ligament injury he sustained last December.