Valetini has been called into the Brumbies' starting side for their clash against the NSW Waratahs at Parramatta on Saturday night.

It will be the first time the 20-year-old rookie has started a game since injuring his knee in an early-season showdown with the Waratah on March 15.

But coach Dan McKellar says the time is right to inject the back-rower to relaunch his Wallabies World Cup hopes and 90 kilogram NSW playmaker Bernard Foley is in the firing line.

"Rob's going to play for Australia, there's no doubt about that," McKellar said. "But let's just get him to string some games together and get back on the park.

"The plan was to build up his minutes and give him some confidence, then expose him when the time was right. I feel like the time is right.

Winger Henry Speight has been ruled out for at least one week with a foot sprain, paving the way for Andy Muirhead to start on the wing.

Valetini, the 20-year-old rookie already tipped for Wallabies duties, gets his chance to be the starting blindside flanker to relaunch his World Cup ambitions.

Valetini has played two games from the bench since injuring his knee in the clash against the Waratahs on May 15.

"Rob's going to play for Australia, there's no doubt about that," McKellar said. "But let's just get him to string some games together and get back on the park.

"The plan was to build up his minutes and give him some confidence, then expose him when the time was right. I feel like the time is right.

"He has that physical presence and can change the course of a game. He's 117, 118 kilograms of granite coming at you, I'm sure Bernard [Foley] is looking forward to that."

BRUMBIES NEWS

The Brumbies will be aiming for their fifth consecutive win when they play at the new $350 million Parramatta stadium for the first time.

They can secure their play-off spot with a big win against NSW and breakthrough for the club's longest winning streak since 2007 if they continue their superb form.

Competition for Wallabies spots will add extra incentive for both teams in the ACT-NSW clash, but Valetini won't get to measure himself against Wallabies flanker Ned Hanigan.

Hanigan has been ruled out with concussion, while Canberra junior Tom Staniforth has been promoted to start in the second row.

The Waratahs have decided not to rest five of their stars as per an agreement with Rugby Australia, meaning NSW coach Daryl Gibson could be forced to leave them out of a last-round match next week when finals spots are up for grabs.

The Waratahs are nine points behind the Brumbies, but are still in contention for a top-eight berth and will need Michael Hooper, Bernard Foley, Kurtley Beale, Sekope Kepu and Rob Simmons on the field for as long as possible to reach the finals.

"[Resting players this week] would be another kick the game doesn't need. I think we want to see the best players and we want to play against the best players," McKellar said.

"There's a lot on the line for us, there's a lot on the line for them, there's a lot on the line for individuals [this week]. It will be on.

"The first 20-25 minutes won't be a place for the faint-hearted. We've got to get our areas right."

SUPER RUGBY ROUND 17

Saturday: NSW Waratahs v ACT Brumbies at Parramatta, 7.45pm.

Brumbies: 1. James Slipper, 2. Folau Faingaa, 3. Allan Alaalatoa, 4. Rory Arnold, 5. Sam Carter, 6. Rob Valetini, 7. Tom Cusack, 8. Pete Samu, 9. Joe Powell, 10. Christian Lealiifano, 11. Toni Pulu, 12. Irae Simone, 13. Tevita Kuridrani, 14. Andy Muirhead, 15. Tom Banks. Reserves: 16. Connal McInerney, 17. Scott Sio, 18. Les Leuluaialii-Makin, 19. Darcy Swain, 20. Jahrome Brown, 21. Lachlan McCaffrey, 22. Matt Lucas, 23. Tom Wright.

Waratahs: 1. Tom Robertson, 2. Damien Fitzpatrick, 3. Sekope Kepu, 4. Tom Staniforth, 5. Rob Simmons, 6. Lachlan Swinton, 7. Michael Hooper, 8. Michael Wells, 9. Nick Phipps, 10. Bernard Foley, 11. Curtis Rona, 12. Lalakai Foketi, 13. Adam Ashley-Cooper, 14. Alex Newsome, 15. Kurtley Beale. Reserve: 16. Andrew Tuala/Tolu Latu, 17. Harry Johnson-Holmes, 18. Chris Talakai, 19. Jed Holloway, 20. Will Miller, 21. Jake Gordon, 22. Tautalatasi Tasi, 23. Cam Clark.