Vincent Kompany will have a scan on Sunday on a potential groin injury sustained during Belgium's goalless draw with Portugal in Brussels.
The Manchester City captain was forced off the pitch 10 minutes into the second half after appearing to hurt himself when lunging for the ball.
Kompany's fitness has been a long-term issue, with a series of injuries over the past five seasons, although he has been able to play without problems for his club since January.
"You could feel that when he came off we were all very much worried," Red Devils coach Roberto Martinez told Sky Sports News.
"He said he felt discomfort in his groin when he walked off the pitch. He's not a young player, he knows his body. At that point it was the right time to come off."
Martinez is due to name his final 23-man squad for the World Cup on June 4.
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