Arsenal midfielder Aaron Ramsey could be missing for up to six weeks because of a serious thigh injury.
The Gunners midfielder, 25, came off just 16 minutes after coming on as a substitute in the FA Cup win against Hull City on Tuesday.
The Welshman, who has a history of injury, was assessed on Wednesday but is due to have a more thorough scan at some point on Thursday.
After the game Arsene Wenger admitted he feared the damage was "serious".
With just three months until the European Championships kick off in France, Ramsey is potentially facing a race to be fit enough to star for Chris Coleman's team.
The worst-case scenario would see Ramsey ruled out for the rest of the season.
There was some good news for Wenger and Arsenal, however, with midfielder Jack Wilshere returning to light training.
The England man hasn't played a game this season.