The Stormers' 33-7 win over Ulster has come at a cost, with Evan Roos and Leolin Zas both picking up knee injuries during the match in Cape Town.
Zas departed before half-time, while Roos — who scored one of the Stormers' five tries with a solo run — was replaced in the second half and was visibly distressed as he left the field. John Dobson indicated Roos's injury could be a medial ligament problem, though the forward had not yet been scanned at the time of speaking.
"It looks like a medial ligament, and he hasn't been scanned yet, but it could be serious," Dobson said. "It's not an ACL, so it could be six weeks or it could be a month."
The Stormers were also dealt a pre-match blow when Bongi Mbonambi, who had only joined the squad from the Sharks in the preceding 24 hours, reported a sore hamstring at the captain's run and was replaced in the matchday squad by Altus Rabe. Dobson described the setback as precautionary and said Mbonambi could be available next week.
The hooker absences compound an already severe positional crisis, with Deon Fourie, André-Hugo Venter, JJ Kotzé and Lukhanyo Vokozela all currently sidelined.
On Ben-Jason Dixon, Dobson confirmed the lock is managing a delayed concussion and that the medical staff have decided to let him return to play in his own time. Keke Morabe, Ruan Ackermann and Cheslin Kolbe are all expected back ahead of the Stormers' clash against the Sharks in early December, with Kolbe's return made more pressing by the injury to Zas.