The Stormers are set to face the Chiefs in Saturday's quarter-final at Newlands without fly-half Jean-Luc du Plessis, who is battling to overcome an akle injury.
Du Plessis and right wing Kobus van Wyk, who limped off in the Stormers' 52-24 victory over the Kings in Cape Town on Saturday, are the big injury concerns for the Stormers.
Their head coach Robbie Fleck admitted after that match that he is particularly concerned about Du Plessis' fitness.
"The Jean-Luc injury is the more serious of the two, and it doesn’t look good at the moment,” said Fleck.
"Kobus should be okay as it is a more positive feedback on him.
"We will reassess the injuries on Monday, and I don’t want to speculate, but Jean-Luc’s ankle injury looks like syndesmosis, which normally means you’re out for four months.
"There’s nothing we can do about it and we must just deal with it.”
The men from the Cape's back-up fly-halves Robert du Preez and Brandon Thomson have seen little Super Rugby action this season although it looks like Fleck will be forced to throw one of them in at the deep end this weekend.
"Rob has played well (in the Currie Cup) and we will reassess the situation on Monday," added Fleck.
"Thommo got a bit of game time against the Kings, which was important. He had a bit of a nervous start with a high pass, but after that he settled nicely.
"He hasn’t had much game time with us, but he has been training with us for the last 10 weeks.
“Every time he has been asked to step up, he has delivered. He has been training with us for 10 weeks, and he slotted in perfectly against the Kings.”