Cape Town - Schalk Burger's injury-enforced absence comes as a huge blow to the Stormers who are desperate to win an away game for the first time this season when they clash with the Sharks in Durban on Saturday.
Burger's neck injury has not healed sufficiently and Stormers' coach Allister Coetzee said the flanker required at least 10 days to recover after the Cheetahs' game at Newlands last week.
"It is a huge blow for us but Schalla's neck spasms were always going to be a 10-day injury," said Coetzee at Thursday's team announcement in Bellville.
"He has made massive progress but he's not ready to play this week. It is not the sort of injury that you can hide.
"I would have liked to have gone into the 'Shark Tank' with the likes of Schalla, Jean de Villiers, Scarra Ntubeni and Gio Aplon to just front up against the Sharks with experienced players. We will be up against a team that has a pack loaded with Springboks so we'll need a side that will pitch up with intensive physicality."
Eighthman Duane Vermeulen will lead the side this week.
The Stormers suffered another injury blow when prop Oli Kebble was struck down by an ankle injury at training on Tuesday. His absence has opened the way for loosehead prop Sti Sithole to be named on the substitutes' bench.
The experienced Brok Harris has also been hit by a recent injury.
Stormers coach Matt Proudfoot said as a result of injuries several young props will be doing duty on Saturday against the Sharks' Springbok front row of Tendai 'Beast' Mtawarira, Jannie and Bismarck du Plessis.
"It is not in the character of these players to be overawed when playing against Springboks," said Proudfoot.
"Props like Sti, who played for the SA under-20 side, and Martin Dreyer, who was playing for Potch (North-West University) in Varsity Cup, are still under the age of 24 years.
"They want to test themselves against the best and the Sharks offer them that chance. They'll relish the challenge and we're looking to bring on Dreyer for Pat Cilliers in the second half."
Argentinean lock Manuel Carizza has been named on the bench and will get a taste of Super Rugby for the first time in 10 weeks. In his absence, Michael Rhodes and rookie Ruan Botha have blossomed as a lock pairing and that has helped to stabilise the Stormers' set-piece.
"The improvement in our set-piece has come about mainly because of selection consistency," said Proudfoot.
"The problem arises when you have to bring in more than one player from one week to the next because it changes the dynamics of the pack. Now we're able to improve because we only have to make one change at a time."
Carizza looked in great jumping form at training this week and he will provide a significant boost at scrum and line-out time when he enters the fray in the second half.
15. SP Marais, 14. JP Pietersen, 13. S’bura Sithole, 12. Paul Jordaan, 11. Lwazi Mvovo, 10. Francois Steyn, 9. Cobus Reinach, 8. Willem Alberts, 7. Tera Mtembu, 6. Marcell Coetzee, 5. Stephan Lewies, 4. Etienne Oosthuizen, 3. Jannie du Plessis, 2. Bismarck du Plessis (captain), 1. Tendai Mtawarira
Substitutes: 16. Kyle Cooper, 17. Dale Chadwick, 18. Lourens Adriaanse, 19. Ryan Kankowski, 20. Keegan Daniel, 21. Charl McLeod, 22. Tim Swiel, 23. Heimar Williams
15. Jaco Taute, 14. Cheslin Kolbe, 13. Juan de Jongh, 12. Damian de Allende, 11. Sailosi Tagicakibau, 10. Kurt Coleman, 9. Nic Groom, 8. Duane Vermeulen
(captain), 7. Siya Kolisi, 6. Nizaam Carr, 5. Ruan Botha, 4. Michael Rhodes, 3. Pat Cilliers, 2. Deon Fourie, 1. Alistair Vermaak
Substitutes: 16. Stephan Coetzee, 17. Sti Sithole, 18. Martin Dreyer, 19. Jean Kleyn, 20. Manuel Carizza, 21. Dylon Frylinck, 22. Demetri Catrakilis, 23. Peter Grant