Arsenal defender Sead Kolasinac will be out for between eight and 10 weeks with an injury to his left knee.
Kolasinac, 25, suffered the injury during Wednesday's friendly with Chelsea in the International Champions Cup in Dublin.
The Bosnia-Herzegovina full-back hurt his knee in a challenge with Victor Moses and Gunners boss Unai Emery said he would have a scan.
Kolasinac is expected to miss up to eight Premier League games.
The former Schalke player is also likely to be absent for two Europa League group matches and the third round of the Carabao Cup.
Meanwhile, Wales midfielder Aaron Ramsey is hoping to return to training next week after a calf problem.


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