Arsenal fear summer signing Jurrien Timber could be out for an extended period.
The Dutch centre half, who can also play right back, has suffered a knee injury in their first Premier League game.
Timber could be out for many months after pulling up against Nottingham Forest on Saturday.
Per The Mail, Arsenal fear the 40 million summer signing from Ajax may have an anterior cruciate ligament injury.
Such an issue may keep him out for most of the coming season, which would be a devastating blow to manager Mikel Arteta.
Timber was signed to give the Gunners more options and better quality depth in defense.