Arsenal will have to wait before they learn the full extent of Carl Jenkinson's knee injury.
The defender was taken off during the Gunners' 1-0 Champions League win against Marseille on Wednesday, and it is likely that he will have to wait until he returns to England before he has a scan.
"It is a knee injury and no-one knows what he has," said manager Arsene Wenger.
Arsenal's win at the Stade Velodrome has moved them above their French rivals to the top of Group F.