Toomua suffered a knee injury last weekend and is set to miss what looms as a make-or-break match on Friday night for the Brumbies finals hopes.

Versatile back Robbie Coleman will shift to inside centre and James Dargaville will be called up for his first start of the season on the wing.

But in good news for the stuttering Brumbies, their front-row trio of Stephen Moore, Ben Alexander and Scott Sio is back in the starting XV with lock Rory Arnold also returning to the No. 4 jersey.

Brumbies coach Stephen Larkham has made 12 changes in the past two weeks as his team struggles to gain any momentum in the middle of the year.

The Brumbies have slipped down the ladder and are in danger of being blown out of the finals contest if they fail to get their form back on track this weekend.

It's unclear how long the Brumbies will be without Toomua after he returned to Australia battered and bruised from a loss to the Otago Highlanders.

Coleman will team up with Christian Lealiifano in the playmaking role, with Canberra Milk jumping on board to offer an incentive for the Brumbies to break their try-scoring shackles.

Canberra Milk will donate $4000 for each try up to $20,000 to the Domestic Violence Crisis Service if the Brumbies can find their attacking groove.

"We're creating a lot of opportunities, it's just a matter of finishing them off," Lealiifano said.

"... I feel like we're working into our shape rather than looking to create. That's a big onus on the playmakers ... and the backs have to light up with opportunities on the edge."

The Toomua injury blow came as Larkham declared his intent to re-sign with the Super Rugby franchise despite a back-room war, saying boardroom instability will not affect his contract decision.

Larkham will continue to focus on re-signing and recruiting players and announcements are expected to be made in the coming weeks as the former Wallabies playmaker starts building for the future.

Larkham had been working with former chief executive Michael Jones to finalise a deal to keep him in Canberra before Jones accepted a payout to leave the club.

That has left Larkham's future in the air and the board is to take charge of negotiations.

"My focus through negotiations has been firmly on staying in Canberra," Larkham said. "I was born in Canberra, grew up in Canberra and played for the Brumbies when they first started. I still feel there's work to be done here.

"Some players are concerned with who the coach is, others just get on with the job and are happy with the environment and culture here.

"My intention is certainly to stay here, I'm not going to hide that. But there's still a lot of discussions to be had to get to that stage.

"...There's a lot to be done [off the field], but none of that will influence my decision."

The fallout from Jones' departure is still lingering in the background and tension remains between the Brumbies and the University of Canberra.

Brumbies officials have met with the ACT government to discuss a tumultuous six weeks and how the organisation plans to get back on track.

The Brumbies will try to put the focus back on rugby when they play the Bulls at Canberra Stadium.

The Brumbies are level with the NSW Waratahs and two points behind the Melbourne Rebels in the battle for Australia's guaranteed finals spot.

Lealiifano hoped returning home could spark the Brumbies attack, and said Larkham was a vital cog in the club chasing a drought-breaking title.

"Everyone's contract stuff is different, and [Larkham] is someone that everyone would ideally like to see stay around," Lealiifano said.

"He's selfless like that. Hopefully he can stay around, I'd love to have him around. He's a fantastic coach and growing into an unbelievable coach. The more we can keep him around, the better we'll be."

SUPER RUGBY ROUND 11

Friday: ACT Brumbies v Pretoria Bulls at Canberra Stadium, 7.45pm. TV time: Live on Fox Sports 2. Tickets available from Ticketek.

Brumbies team: 15. Aidan Toua, 14. James Dargaville, 13. Tevita Kuridrani, 12. Robbie Coleman, 11. Nigel Ah Wong, 10. Christian Lealiifano, 9. Tomas Cubelli, 8. Jarrad Butler, 7. David Pocock, 6. Scott Fardy, 5. Sam Carter, 4. Rory Arnold, 3. Ben Alexander, 2. Stephen Moore, 1. Scott Sio. Reserves: 16. Josh Mann-Rea, 17. Allan Alaalatoa, 18. Ruan Smith, 19. Tom Staniforth, 20. Blake Enever, 21. Jordan Smiler, 22. Joe Powell, 23. Lausii Taliauli.

Bulls team: 15. SP Marais, 14. Travis Ismaiel, 13. Jesse Kriel, 12. Jan Serfontein, 11. Bjorn Basson, 10. Francois Brummer, 9. Piet van Zyl, 8. Hanro Liebenberg, 7. Arno Botha, 6. Lappies Labuschagne, 5. Marvin Orie, 4. RG Snyman, 3. Marcel van der Merwe, 2. Adriaan Strauss, 1. Trevor Nyakane. Reserves: 16. Bandise Maku, 17. Lizo Gqoboka, 18. Werner Kruger, 19. Jannes Kirsten, 20. Roelof Smit, 21. Rudy Paige, 22. Tian Schoeman, 23. Dan Kriel.