Swansea midfielder Tom Carroll, on loan from Tottenham, faces up to six weeks out after damaging ankle ligaments.
Carroll, 22, suffered the injury as he scored the goal which gave England Under-21s a 1-0 win away against the Czech Republic last Friday.
It means Carroll may have played his last game for the Swans, as his loan expires at the end of the season.
Swansea are also monitoring winger Jefferson Montero, who was injured in Ecuador's friendly defeat by Mexico.
The extent of Montero's muscle strain is unknown but the 25-year-old, who has struggled with injuries this season, is a doubt for Saturday's Premier League match against Hull.
England Under-21 captain Carroll, who has scored once in 18 appearances for Garry Monk's Swansea side, will face tough competition for a place in Swansea's midfield if he does manage to recover before the end of the season.
Ki Sung-yueng, Jonjo Shelvey, Gylfi Sigurdsson, Leon Britton and January signing Jack Cork all appear to be ahead of Carroll in the Liberty Stadium hierarchy.