England and Bath prop Will Stuart will be out for “some time” after going off injured in the defeat by South Africa.
Stuart came on as a replacement at half-time but went down with an injury following a scrum in the final few minutes of the 27-13 loss.
The 26-year-old scored two tries to rescue a draw against New Zealand earlier in England’s autumn campaign.
“Medics are assessing him to see how long it will be, but it’s not looking good,” Bath coach JP Ferreira said.
Stuart, who has been capped 25 times by England, played five matches for Bath this season before suffering a knee injury in their loss to Saracens in October.
He recovered in time to be called up to the national squad by Eddie Jones for the final two matches of the Autumn Nations Series.
“It’s sad for him because he’s come back, done really well, got into the England set up again and now he’s injured again,” Ferreira told BBC Radio Bristol.
“He’s had a bad run of injuries, hopefully this is his last.”
Bath are also set to be without second rower Quinn Roux for the foreseeable future after he suffered a knee injury in the team’s narrow loss to the Barbarians in a friendly on 20 November.
Bath next face Harlequins at the Recreation Ground on Friday having won their last three Premiership games.
“Quinn did his knee in that game and he’s going to be out for a lengthy spell as well, trying to get it right for hopefully the start of the new year but he’ll be out for some time,” Ferreira added.
“It certainly is not getting easier with the injuries.”