Head coach Warren Gatland says fly-half Dan Biggar is looking at two weeks out after pulling a chest muscle in Wales’ convincing win over Australia.
Biggar left the field after just 12 minutes and was replaced by Gareth Anscombe who produced a man-of-the match performance in the 40-6 victory.
“Dan’s stretched his pec, we are not too sure,” Gatland said.
“I haven’t spoken to the medics but I spoke to Dan and they are saying it is probably a couple of weeks.”
Wales face Georgia in Nantes on 7 October before a quarter-final in Marseille the following weekend after becoming the first team to achieve last eight qualification in the 2023 World Cup.
“We have got 13 days’ break before we take on Georgia so that potentially rules him out of that match, just to recover,” said Gatland.
“It’s not a significant injury, just a pec strain.”
In a 23-point haul, Anscombe kicked six penalties, a drop-goal, a conversion and chipped a perfectly weighted kick for Nick Tompkins to score.
“He really stepped up tonight,” said Gatland.
“He was a bit rusty against Portugal but we’ve picked him for his experience and he controlled the game well.
“We’ve got two experienced 10s and a young, up-and-coming 10 so we’re in a pretty good place.
“It was pleasing to see him goal-kick that well and I thought he made some really good decisions.”