Henry Speight has been ruled out with a rib injury, allowing Joseph Tomane to join the starting XV on the wing and Tevita Kuridrani to join the bench.

In the only other change to the squad, prop Ruaidhri Murphy will be given an extra week to overcome a groin injury and Scott Sio joins the bench as the back-up front-rower.

The Brumbies flew to Melbourne on Thursday morning for a ''must win'' match against the Rebels.

The Brumbies have only lost one of their four matches against the Rebels in the past two seasons.

But that one loss triggered a downward spiral to the worst season in the club's history as Andy Friend was sacked as coach and the team finished 13th on the ladder.

Now with Jake White in charge, the Brumbies have set their sights on making the finals for the first time since 2004.

White said the Brumbies could not afford to lose to Melbourne with a bye next weekend followed by a crucial clash with arch rivals the NSW Waratahs.

''We must win [in Melbourne],'' White said.

''There's no reason why we shouldn't win. People have talking about us having all our eggs in one basket for the game against the [Queensland] Reds in round one, but that's not true.

''We knew the Reds would be tough because they have been champions, but we've never taken our eye off that we had a two-game block before the first bye.

''We will never underestimate the Rebels.''

Tomane started the season on the bench last weekend with Speight and Clyde Rathbone taking the two available wing spots.

The former NRL speedster had an outstanding debut Super Rugby campaign last year and was rewarded with his first Wallabies cap before injury halted his momentum.

''I know I have to be more consistent this year if I want to get to where I want to go with my achievements,'' Tomane said.

''The first focus is the Brumbies and trying to help the team and then Wallabies or whatever will follow.

''It's a level playing field for me now [with Wallabies selection]. Clyde is such a good guy to learn off, he's been there and done it all so having someone like him around is really beneficial for me.

''Rath is a role-model and I can see first hand what it takes to be a Wallabies winger.''

Super Rugby round two

Friday: ACT Brumbies v Melbourne Rebels at AAMI Park, 7.40pm. Live on Fox Sports 2.

Brumbies: 1. Ben Alexander, 2. Stephen Moore, 3. Dan Palmer, 4. Scott Fardy, 5. Sam Carter, 6. Peter Kimlin, 7. David Pocock, 8. Ben Mowen, 9. Nic White, 10. Matt Toomua, 11. Clyde Rathbone, 12. Christian Lealiifano, 13. Andrew Smith, 14. Joseph Tomane, 15. Jesse Mogg. Reserves: 16. Siliva Siliva, 17. Scott Sio, 18. Colby Faingaa, 19. Fotu Auelua, 20. Ian Prior, 21. Tevita Kuridrani, 22. Robbie Coleman.