Exeter are awaiting news on the extent of England winger Immanuel Feyi-Waboso's shoulder injury.
The 22-year-old dislocated his shoulder early in Chiefs' 28-10 loss at Sale on Saturday.
Feyi-Waboso, who has won nine England caps, will not feature in their home Premiership match against Gloucester on Sunday, 29 December.
It is the latest blow to an Exeter side who have still to win a Premiership or Champions Cup match this season.
"Initially it's popped out, popped back in, and now we've just got to wait and see what the damage is," Exeter director of rugby Rob Baxter told BBC Sport.
"When it first popped back, I don't think he seemed to be in too much pain because he was a bit 'can I not carry on?'. The medics had to go 'clearly not, you've just had a shoulder dislocation'.
"So we're hopeful that that means there's not too much damage.
"We've just got to assume that the likelihood is he's got some shoulder damage from a shoulder dislocation and we'll have to see how bad it is."
Feyi-Waboso has scored six tries in 10 domestic and European starts for Exeter this season, as well as scoring England's only try in their dramatic 24-22 loss to New Zealand last month.
The medical student also scored tries in all three of England's summer tour matches - touching down against Japan and twice against the All Blacks.
"He's a very good player, he creates moments for us," Baxter added.
"Where we're fortunate is we've got the rest of our back three up and running now, whereas we didn't have Ben Hammersley and Tommy Wyatt at the start of the season.
"We've got good cover there, but unfortunately Manny's now going to be out for a period and it's not ideal either for ourselves or for England."