Arsenal have confirmed that head coach, Mikel Arteta, will be without three first-team players when they travel to Crystal Palace on Saturday.
Hector Bellerin is yet to fully recover from a tight right hamstring and the fullback will not feature in the London Derby.
Calum Chambers has had surgery on ruptured anterior cruciate ligament. His rehabilitation process is expected to take up to nine months.
Left-back Kieran Tierney misses out with a dislocated shoulder but should be back in full training by March.
A club statement reads: “Hector Bellerin – Tight right hamstring. Being assessed ahead of Crystal Palace (a).
“Calum Chambers – Left knee. Ruptured anterior cruciate ligament of his left knee during Chelsea (h) on 29 December. Successful surgery completed. Rehabilitation process expected to take between six to nine months.
“Kieran Tierney – Right shoulder. Dislocated right shoulder during West Ham Utd (a) on 9 December. Successful surgery completed. Rehabilitation process expected to take around three months, aiming to return to full training in March.”