Arsenal have announced that defender Sead Kolasinac will be sidelined for up to 10 weeks after suffering a knee injury.
The 25-year-old had to be helped off the pitch during the Gunners' International Champions Cup victory over London rivals Chelsea in Dublin on Wednesday night.
Kolasinac, who was involved in a clash with Victor Moses, was replaced 20 minutes from the end of the contest, which the Gunners won on penalties.
In an update on their official website, Arsenal revealed that the Bosnia and Herzegovina international "sustained an injury to his left knee" and is expected to be out for between eight and 10 weeks.
The North Londoners also confirmed that Aaron Ramsey "developed tightness in his right calf" prior to the game in the Republic of Ireland, but will aim to return to training next week.
Unai Emery's side play their final pre-season friendly on Saturday as they take on Italian giants Lazio in Stockholm.
