Arsenal on-field captain and senior centre-back, Laurent Koscielny, has been ruled out of Wednesday’s London derby against West Ham United with the Achilles tendon injury he suffered on Sunday against Manchester City.

Petr Cech is also unavailable for a fixture that will have a major bearing on the future of manager Arsene Wenger, who has been told that he must accept significant off-field change this summer if a new contract is to be agreed.

Arsenal have been looking across Europe at candidates for a sporting director role that would stretch beyond just recruitment and see the club move towards a more continental set-up.

Chief executive Ivan Gazidis also wants to drive improvement in the medical, analytics and scouting departments, with Wenger’s unknown future and likely off-field change causing considerable uncertainty among backroom staff.

Arsenal believe that change is now necessary and, while a decision on Wenger has not been made, he would be expected to fulfil his own stated desire to “reinvent” himself if he stays on.