Arsenal face a major injury scare after Martin Odegaard required a knee brace following their 2-0 victory over West Ham — his third injury in less than two months.
The Gunners captain went down with discomfort in his left knee in the opening 20 minutes of the match.
He called for medical attention and returned to the pitch, but 10 minutes later had to be substituted off and looked distraught.
It follows two separate injuries to his right shoulder this season — against Nottingham Forest and Leeds — before his start against Olympiacos midweek where the Norwegian put in man of the match display.