Uruguay coach Oscar Tabarez says he is “worried” after Edinson Cavani limped out of their 2-1 win against Portugal with a suspected hamstring injury.
Cavani, 31, scored both goals as Uruguay booked a quarter-final with France next Friday – but left the pitch with 16 minutes remaining.
“We don’t have a lot of time to recover,” said Tabarez.
“Right now, we are only worried but we don’t know how serious the injury really is.”
Cavani – Paris St-Germain’s record goalscorer – said: “I hope the pain turns out to be nothing.
“I just felt something at one point and couldn’t recover. I hope (to be fit), I’ll do everything to make sure I can take to the field with my teammates,
“I am really happy to see all these people partying.”