After days of turmoil, court battles, power struggles and uncertainty, it's easy to forget the Brumbies are on a South African mission to beat the Free State Cheetahs in Bloemfontein on Sunday morning.

Coach Stephen Larkham has moved to inject energy into his line-up in one of the most dramatic weeks of the club's history as he makes changes for the clash against the Cheetahs.

Robbie Coleman and Tongan powerhouse Ita Vaea will be thrown into the starting side as the Brumbies on-field unit take centre stage.

Prop Scott Sio says the players must own up to their loss against the Cape Town Stormers last week and rectify their deficiencies to end their three-week road trip with a win.

On paper most expect the Brumbies to beat the Cheetahs, and their record of winning eight of the 11 matches between the teams suggests they are in pole position.

But Sio is aware that any lapse will cost the Brumbies dearly and their fast-start to the season will be evaporated.

"Each game is a must win these days, every team you come up again beat you," Sio said.

"We know what we did and we know what we did wrong and that we have to improve on [in the game against the Stormers]. We have to front up physically in the general play stuff.

"We have to be more consistent in every area of the game. More for me we've got to make sure the belief in the group doesn't die down.

"After a loss [like against the Stormers] you've got to make sure the belief is still strong in the group because the end goal is to win. You're going to have ups and downs in this competition, it's about how we bounce back."

Brumbies winger Henry Speight had surgery on Thursday to repair the fracture above his left eye after returning to Australia and being ruled out for between four and eight weeks.

It remains unclear how the injury will affect his Australian sevens prospects and his hopes of making the team to play at the Rio Olympic Games.

Vaea made the dash to South Africa this week when Jarrad Butler was ruled out of the tour with a knee injury, which is set to keep him out of action for up to six weeks.

Prop Ruan Smith gets his first chance of the season on the bench with Les Leuluaialii-Makin dropping out of the game-day squad, hooker Robbie Abel is set to earn his first Super Rugby cap as the back-up hooker to replace the suspended Josh Mann-Rea and James Dargaville steps up on the bench.

The Brumbies have declared the club's off-field woes will not distract them from their goal of leaving South Africa on a high.

Larkham brought the squad together earlier this week to tell them chief executive Michael Jones had been stood down by the Brumbies board.

He had to address them again when Jones launched legal action and was successful in gaining an injunction to return to his job less than 24 hours after being stood down.

The Brumbies playing squad will walk back into a storm when they return to Canberra next week, but are adamant they can avoid the saga to focus on winning games.

The Brumbies have won three of their four games this season, suffering their first loss against the Stormers last weekend.

"This week [has] been a big week for us to make sure we get everything on point and that we're ready to go against the Cheetahs," Sio said.

The Brumbies lost the penalty count 11-5 against the Stormers and it showed in an end result of 31-11.

"It's tight margins in this competition and there are moments in each game that can win it, that all piles up and either go your way or they don't. We'll be ready to go," Sio said.

SUPER RUGBY ROUND FIVE

Sunday: Free State Cheetahs v ACT Brumbies at Bloemfontein, 12.05am. TV time: Live on Fox Sports 2.

Brumbies: 15. Aidan Toua, 14. Robbie Coleman, 13. Tevita Kuridrani, 12. Matt Toomua, 11. Joseph Tomane, 10. Christian Lealiifano, 9. Tomas Cubelli, 8. Ita Vaea, 7. David Pocock, 6. Scott Fardy, 5. Sam Carter, 4. Rory Arnold, 3. Ben Alexander, 2. Stephen Moore, 1. Scott Sio. Reserves: 16. Robbie Abel, 17. Allan Alaalatoa, 18. Ruan Smith, 19. Tom Staniforth, 20. Jordan Smiler, 21. Michael Dowsett, 22. James Dargaville, 23. Nigel Ah Wong.