Belgium boss Roberto Martinez confirmed Kevin De Bruyne and Eden Hazard both suffered injuries in the 1-0 win over Portugal on Sunday.
Manchester City star De Bruyne injured his ankle, while Hazard was brought off with a muscle injury.
Martinez said it was too early to provide a return date for the pair.
"It's too early to say how they are doing,' Martinez said after the game.
"With Kevin, it's the ankle – he couldn't really turn in the second half. With Eden it's the muscle, but we have to wait for a diagnosis."
