Tom Hooper and Rod Iona have a combined 21 games' worth of Super Rugby experience but coach Dan McKellar says his Brumbies have "no excuses" as they prepare to tackle their toughest task.

Test-capped duo Valetini [hamstring] and Lolesio [concussion protocols] have been ruled out of a clash between Super Rugby's heavyweights at Canberra Stadium on Friday night.

Iona will take the reins at flyhalf while Hooper shifts from lock to earn a start in the No. 6 jersey as Valetini races the clock to be fit in time for the finals. Lolesio is expected to return to face the Blues next week.

Samoan international Iona has already started in three games this year when Lolesio was sidelined with an ankle injury, while Hooper was trusted to make his debut against the Crusaders in Christchurch last year. It's enough to give McKellar confidence they will rise to the task.

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"There's no excuses from our end. Rod has played plenty of footy this year for us and has trained at 10 all year, and he's prepared and ready to go," McKellar said.

"He's got good experience, that's been the whole point around us rotating and making sure we provide opportunity, so if this happens, you're going to get injuries, guys are ready to play.

"It's the same with Tommy Hooper isn't it? I'm really excited there, a young Owen Finegan-type boy so we'll see how big Hoopy goes.

"He's excited at the best of times, Hoops. When I told him he was wearing No. 6 and wasn't at tighthead lock, I think that excites any lock. He's a good young footballer, great attitude, and has been superb for us off the bench and in the game he started.

"He's not Rob Valetini, I just want him to play how Tommy Hooper plays and bring a whole lot of repeat efforts, work rate and physicality.

"We understand that Bobby is in a rare patch of form and is playing really well, but the boys have got full confidence in the next guy that steps up."

Lachlan Lonergan and Allan Alaalatoa return to the front-row alongside James Slipper. Folau Fainga'a will be the finishing hooker. Scott Sio and Tom Ross are the props on the bench, with Sefo Kautai rotated out of the side.

Hooper's elevation to the starting XV brings Luke Reimer onto the bench in the only other change to the matchday 23.

"Canberra hasn't got a Test match this year or in the near future, and this is probably going to be as close to it as possible with the amount of All Blacks they'll have in their group and the amount of potential Wallabies we've got in our group," McKellar said.

"It's the Brumbies and the Crusaders, there's a lot of history behind the occasion and the fixture. We just want people to get behind it."

SUPER RUGBY PACIFIC ROUND 13

Friday: ACT Brumbies v Canterbury Crusaders at Canberra Stadium, 7.45pm. Tickets from Ticketek. Broadcast live on Stan Sport.

Brumbies team: 1. James Slipper, 2. Lachlan Lonergan, 3. Allan Alaalatoa (c), 4. Darcy Swain, 5. Cadeyrn Neville, 6. Tom Hooper, 7. Jahrome Brown, 8. Pete Samu, 9. Nic White, 10. Rod Iona, 11. Andy Muirhead, 12. Irae Simone, 13. Len Ikitau, 14. Tom Wright, 15. Tom Banks. Reserves: 16. Folau Fainga'a, 17. Scott Sio, 18. Tom Ross, 19. Nick Frost, 20. Luke Reimer, 21. Rory Scott, 22. Ryan Lonergan, 23. Ollie Sapsford.

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