Henrikh Mkhitaryan is a doubt for Arsenal's Premier League meeting with Everton due to an ankle injury.
The Armenia international sustained the injury during Thursday's Europa League win against Vorskla.
Mkhitaryan will be assessed ahead of Sunday's home game against the Toffees, Arsenal said in a statement, but he may miss the match.
The Gunners provided an update on their other injured players, with Laurent Koscielny beginning to train outside as he recovers from an Achilles injury.
Job well done by and Star man for the Gunners? September 20, 2018
Sead Kolasinac (knee), Ainsley Maitland-Niles (broken leg) and Carl Jenkinson (ankle) are all expected to return to full training in early October.
Arsenal are seventh in the Premier League going into Sunday's clash with the Toffees, having won their last four games in all competitions.
