Arsenal manager Arsene Wenger has admitted that he is still hopeful of having Sead Kolasinac available for next weekend's Premier League meeting with Manchester City.
The Bosnia-Herzegovina international limped off with a knock against Swansea City four days ago and has been ruled out of the Europa League tie against Red Star Belgrade.
Wenger hopes to have his summer signing back to fitness in time for the trip to the Etihad Stadium on Sunday afternoon, although a number of other first-team squad members will likely miss out on both games this week.
"Kolasinac was much better - he will have a test at the end of the week," he told reporters. "He is not ruled out of Sunday's game yet. It's not as bad as we could have feared it at the start.
"[David] Ospina maybe will be available for Sunday. [Calum] Chambers is back in full training but not fit enough to play."
Shkodran Mustafi and Danny Welbeck will both return after the international break, meanwhile, and Santi Cazorla is on course to feature before the year is out.
Daniel Lewis
