Stormers co-captain Juan de Jongh has suffered a hamstring injury which will see him miss out on their Super Rugby derby match against the Bulls at Loftus Versveld on Saturday.
De Jongh, who did not run at full pace during the Sunwolves match last week, has sustained a grade one hamstring strain but is likely to be sidelined for only one week.
The Cape outfit's head coach Robbie Fleck admits that De Jongh had not been pushed in the build-up to the 17-all draw against the Sunwolves in Singapore last week.
"Like I said from Singapore the day after the game, Juan was struggling with the injury a bit during the Sunwolves game," Fleck told reporters.
"He couldn’t run to his full potential. He was battling with it a bit in the build-up to the game but we thought he would be able to play with it.
"It is one of those borderline injuries where you can play at a push.
"But this is an important game for us and obviously we’d like to have our strongest team available for it. So it is a big blow."
Injury to front-row JC Janse van Rensburg, as well, has added insult to injury for Fleck with an ever-growing list of players that are already on the sidelines due to lengthy lay-offs.
The former Lions prop, who will most likely be replaced by Oli Kebble in the starting XV, has been ruled out for up to three months following a knee injury.
Some good news for the Stormers is that Springbok lock powerhouse Eben Etzebeth and the returning-from-suspension wing Leolin Zas will both be back for this week's vital match.
"Eben is definitely ready to go again," Fleck said.
"And it is always good to have a player back from injury or suspension so it is good to have Leolin back in the mix too.
"It is a pity that Juan isn’t playing as the battle between our midfield and their Bok midfield of Jan Serfontein and Jesse Kriel would have been an interesting one.
"But it is what it is and these things happen in rugby."