The Blues have lost lock Scott Scrafton to a training injury, with Josh Goodhue joining prop Sione Mafileo as injury cover.
Coach Umaga said the side is well motivated and determined to build on their winning effort against the Lions last week.
"We are naturally pleased with the result and with many aspects of our performance last week, but we also realize that we must continue to improve every week.
"The Stormers have had the wood on us in recent years and we need to work very hard this week to prepare for what will be another tough encounter here in South Africa.
"There were many parts of our game that were pleasing last week but we gave away two tries and did not cherish our possession enough.
"We can't afford to give the Stormers the same opportunities that we gave the Lions, but at the same time we want to play with the same level of commitment, aggression and belief."
The Blues will chase a second win in South Africa in a season for the first time in 10 years, with the game kicking off at 2.05am NZ time on Sunday.
The team is:
1. Pauliasi Manu, 2. James Parsons ©, 3. Ofa Tuungafasi, 4. Patrick Tuipulotu, 5. Gerard Cowley-Tuioti, 6. Jerome Kaino, 7. Antonio Kiri Kiri, 8. Akira Ioane; 9. Sam Nock, 10. Bryn Gatland, 11. Melani Nanai, 12. Sonny Bill Williams, 13. Rieko Ioane, 14. Matt Duffie,15. Michael Collins.
Reserves: 16. Leni Apisai, 17. Ross Wright or Sione Mafileo, 18. Mike Tamoaieta, 19. Jimmy Tupou, 20. Murphy Taramai, 21. Jonathan Ruru, 22. Stephen Perofeta, 23. George Moala