As it stands, the Blues and Moana Pasifika both sit on 28 competition points, however Moana Pasifika are ahead on the table due to the first tie-breaking metric of most wins.
A bonus-point win for the Blues would put the pressure on their cross-town rivals to do the same.
Should the Waratahs beat the Blues, they would need Moana Pasifika to lose to the Hurricanes if they are to secure sixth on the ladder as they go into the round two points further back.
Blues team to face the Waratahs
Mark Tele’a returns on the right wing for the Blues’ must-win clash against the Waratahs.
It’s one of five changes to the most recent Blues line-up, with Vern Cotter’s side coming into the final round of the regular season fresh off a bye week.
In the forwards, Marcel Renata starts at tighthead prop, while Laghlan McWhannell joins Patrick Tuipulotu at lock and Anton Segner starts at blindside flanker.
In the backs, Finlay Christie starts at halfback, with the return of Tele’a seeing AJ Lam shift to second five-eighths.
After starting last time out, prop Angus Ta’avao and lock Josh Beehre move to the bench, while prop Jordan Lay, loose forward Adrian Choat and halfback Sam Nock join the matchday squad.
Blues: 1. Joshua Fusitu’a 2. Ricky Riccitelli 3. Marcel Renata 4. Patrick Tuipulotu 5. Laghlan McWhannell 6. Anton Segner 7. Dalton Papali’i 8. Hoskins Sotutu 9. Finlay Christie 10. Beauden Barrett 11. Caleb Clarke 12. A.J. Lam 13. Rieko Ioane 14. Mark Tele’a 15. Corey Evans.
Bench: 16. Kurt Eklund 17. Jordan Lay 18. Angus Ta’avao 19. Josh Beehre 20. Adrian Choat 21. Sam Nock 22. Harry Plummer 23. Cole Forbes.
Unavailable: Cam Christie (thumb), Stephen Perofeta (leg), Reon Paul (shoulder), Cam Suafoa (medical, season), Ofa Tu’ungafasi (neck, season), Sam Darry (shoulder, season).