The Dortmund star could miss the rest of the Confederations Cup and the start of next season after suffering a suspected broken leg
Portugal fear Raphael Guerreiro suffered a broken leg in the Confederations Cup victory over Russia.
Guerreiro limped off the pitch after 66 minutes of his side's 1-0 victory over hosts Russia in Moscow on Wednesday.
And Portugal boss Fernando Santos is worried the Borussia Dortmund star, who had earlier set up Cristiano Ronaldo's headed winner, has suffered a serious injury.
"Raphael went to hospital," he said. "We think he might have fractured his leg, unfortunately.