Coach Stephen Kearney confirmed Tuivasa-Sheck was preparing to return to the side after sitting out last week's 24-14 win over Parramatta in Sydney.
"He's all good to go. We might just switch his phone off for the next hour and see what happens," Kearney joked on Radio Sport.
However, interchange second-rower Isaiah Papali'i has dropped out of the Warriors extended squad along with back-up centre Anthony Gelling.
The home side are also without halfback Mason Lino, who was scratched from the line-up last night, after failing to overcome a leg injury suffered last week against the Eels at ANZ Stadium.
Playmaker Blake Green will fill the No 7 role, with usual centre Peta Hiku slotting in at five-eighth, and Gerard Beale coming off the bench to play right centre for the second week in a row.
Kearney was confident his side will cope with the changes and stressed the importance of doing the basics well in defence.
"The guys have reacted pretty well over the course of the last month, we've had a little bit of disruption in giving guys as late as possible to try and get ready to play and guys in and out and it hasn't really affected the group," he said.
"What we recognised last week and what we know about or game is when we do certain areas pretty well we put ourselves right in the contest and one of those is kick-chase.
"Our focus is definitely on our game and our process what we need to get right, and we know if we get the kick-chase right and get an even share of possession then we give ourselves a real chance."
The Warriors are searching for consistency and looking for back-to-back wins for the first time since early April, while the Rabbitohs arrive hunting for a fourth-straight win after beating the Knights, Dragons and Cowboys.
Warriors v Rabbitohs at Mt Smart Stadium, Saturday, 7.30pm
UPDATED TEAM LISTS:
Warriors: 1. Roger Tuivasa-Sheck 2. David Fusitu'a 18. Gerard Beale 4. Solomone Kata 5. Ken Maumalo 3. Peta Hiku 6. Blake Green 8. James Gavet 9. Issac Luke 10. Agnatius Paasi 11. Simon Mannering 12. Tohu Harris 13. Adam Blair
Interchange: 14. Jazz Tevaga 15. Chris Satae 16. Bunty Afoa 20. Karl Lawton
Rabbitohs: 1. Greg Inglis 2. Campbell Graham 3. Adam Doueihi 4. Dane Gagai 19. Robert Jennings 6. Cody Walker 7. Adam Reynolds 8. Thomas Burgess 9. Damien Cook 10. George Burgess 11. John Sutton 12. Angus Crichton 13. Sam Burgess
Interchange: 5. Hymel Hunt 14. Cameron Murray 16. Jason Clark 17. Tevita Tatola