Dembele was carried off following an injury-time tackle by Stoke defender Andy Wilkinson in Tuesday night's 2-0 Carling Cup defeat at the Britannia Stadium.
Hughes was furious with the challenge, which he branded "absolutely ridiculous", and initially feared the £5million summer signing from AZ Alkmaar had broken his leg.
But a scan revealed that Belgium international Dembele, who has scored three goals this season in a fine start to life at Craven Cottage, had sustained only minor ankle ligament damage.
"Moussa had a scan after the initial impact of the injury had settled down," said Hughes. "At the moment it looks like he'll be out for two to three weeks. He should be fit and well after the international break.
"The challenge was unnecessary and we're thankful the injury isn't more serious than it is.
"At the time I was extremely angry and made my feelings known.
"We've been really pleased with what Dembele has produced and he's been a big reason behind the positive start we've had.
"Not to have him available because of a tackle so late in the game is frustrating for everybody."
Source: Team Talk
Source: Team Talk