The German international is expected to be assessed ahead of the showpiece Wembley final but early indications suggest that he may not be risked ahead of the game.
Interestingly, the Premier League’s relatively new medical rules regarding head injuries make it impossible for Gunners boss Arsene Wenger to overrule his medical team, with club doctor and chairman of the Premier League Doctors’ Group Dr Gary O’Driscoll playing a key part in bringing the regulations to the table in 2014.
Alexis Sanchez future completely Arsenal's decision
“With regard to head injuries there has been a perception in the past that you can tough it out, you can play on, you can be brave,” said Dr O’Driscoll in 2014. “I'm very lucky that I work in a club where the manager will take on board everything we recommend as a medical team but it's possible that there are other places that do need that education where it's still regarded as something that you can run off or it's a brave decision to leave a player on.
“We'd really like for everybody involved in the game to accept that concussion is a brain injury. We are acting in your best interests, and the team's best interests. To take a player off is for his short-term, medium-term and long-term benefit.”
Petr Cech suffered a fractured skull over 10 years ago when he was caught by a boot to the head from Reading’s Stephen Hunt while playing for Chelsea.
The Czech shot stopper has played with protective head gear ever since that incident and his case is a more serious example of why head injuries need to be treated in the same respect as every other injury.
Arsenal's defence will be unable to contain Chelsea - Merson
Wenger has previously been criticised for fielding players who are in the ‘red zone’ or only recently recovered from injuries and Arsenal’s defensive crisis ahead of Saturday’s cup final provides a selection headache for the north London underdogs.
Brazilian defender Gabriel is out for six to eight weeks with a knee injury, Laurent Koscielny is suspended after his red card against Everton and Mustafi’s concussion means it’ll be touch and go as to whether he’s involved or not.
Per Mertesacker could start alongside Rob Holding and Nacho Monreal in defence although it remains a possibility that Wenger will revert to his favoured back four due to the lack of pace for Arsenal at the back. Left-back Kieran Gibbs has been training with the squad despite worries over a thigh injury which means a start at left wing back for the Englishman is likely.