Arsenal left-back Oleksandr Zinchenko will undergone a scan on his calf on Monday after missing their 2-1 defeat at Fulham.
Zinchenko was left out of the squad for the trip to Craven Cottage on Sunday and Arsenal face a nervous wait to see how long he could be out.
Jakub Kiwior filled in for Zinchenko but he was hooked at half-time for Takehiro Tomiyasu, who made his comeback after four weeks out with a calf injury.
Tomiyasu is due to head to the Asian Cup next month and Arsenal will be hoping that Zinchenko is not out then too, as they are already light on numbers in defence.
Asked how Zinchenko was, Mikel Arteta said: “We don’t know. He felt something in his calf.
“We will scan him tomorrow and see how far he’s going to miss games.”
Arsenal have had to cope with injuries in defence all season after Jurrien Timber injured his knee in the opening Premier League game of the campaign.
Thomas Partey has also been out since October with a thigh problem and that is a blow because he can fill in at right-back.
Arsenal have slipped to fourth in the Premier League after three games without a win.
“We need to improve,” said Arteta. “We need to win games and in order to do that we need to win games.
“In order to do that we need to do it with players that after 20 League games, we have the chance to be the best in the League with these players.”
