It's understood McKellar is set to be unveiled as the club's new leader on Friday as the team prepares for an attempt to seal its finals fate against the Melbourne Rebels at Canberra Stadium.

The match will be the Brumbies' last home game of the regular season and could be a farewell for Larkham if the team fails to make the Super Rugby finals.

McKellar will step into the top job when Larkham becomes a full-time Wallabies assistant at the end of the season after the Brumbies completed a world-wide search for a replacement.

In they end they are set to settle on a man who has been in their back yard since 2013, with McKellar to take the coaching reins for a new generation.

One of his first tasks will be finalising contracts for a host of players, with many believed to be committed to staying in Canberra to chase a championship under his watch.

The Brumbies had hoped to finalise their search for a new coach in March, but the uncertainty surrounding the future of Australia's franchises clouded the process.

The ARU will axe either the Melbourne Rebels or the Western Force after SANZAAR decided on a Super Rugby overhaul.

Australian Diamonds coach Lisa Alexander and former Brumby Rod Kafer were on a selection panel and McKellar was recommended to the board as the preferred candidate.

"I feel honoured and privileged to be taking over as head coach of this fantastic club," McKellar said. "It's a wonderful club to be part of and I am looking forward to helping shape the future of the Brumbies, on and off the field.

"Having worked with Stephen for several years, and been part of the Brumbies set-up since 2013, I am confident that we have some exciting times ahead of us. We have lots of young talent at the club and are in the process of looking to consolidate our playing resources for next season.

"Working with chief executive Michael Thomson, and general manager of professional rugby and pathways, Damien Hill, we are already preparing for the 2018 season in terms of new acquisitions that will help keep the Brumbies at the forefront of Australian rugby."

McKellar, a former Tuggeranong Vikings coach, will get his chance to put his own stamp on the club while Larkham could still play a valuable role in his new job.

The former champion playmaker will be based in Canberra as part of an ARU strategy to support Super Rugby franchises with extra resources.

But Larkham is refusing to think about the future or the end of his tenure in Canberra as he focuses on clinching a Super Rugby play-off berth.

The Brumbies are nine points ahead of the NSW Waratahs in the Australian conference and can all but seal their finals fate if they topple the Rebels on Saturday night.

The Brumbies' finals hopes appeared doomed after they lost four games in a row, but they resurrected their season on a two-game tour of South Africa and Argentina.

But losing against the Rebels could open the door for their Australian conference rivals and rob Larkham, a two-time Super Rugby winner, of a hometown send off in the finals.

"It will be a sad moment when it's finally realised [after my last game]," Larkham said.

"At this stage the focus and the belief of the team is that we're going to be there in the finals. The outcome will look after itself if we get our preparation right.

"Yes, this could be our last home game. Or it could be our second last, or third or fourth. I don't know yet. Thinking about things that might happen is something we've spoken to the team about not doing.

"So I'm not doing that at the moment. If it's this weekend ... well, we won't know anyway so I'm not treating this like it's going to be my last game."

The Brumbies are working with a host of players and are on the verge of re-signing the bulk of their squad after the ARU lifted a contract ban earlier this week.

McKellar will have a large say in the future while there is also potential for the club to add players from whichever team the ARU decides to axe from the competition.

McKellar led Tuggeranong to two Canberra premier division premierships before a stint coaching in Japan.

But he returned to the capital to work as an understudy to Laurie Fisher and Larkham, and is set to get his chance to lead the program into the coming seasons.

SUPER RUGBY ROUND 15

Saturday: ACT Brumbies v Melbourne Rebels at Canberra Stadium, 7.45pm. Tickets available from Ticketek.

Brumbies team: 15. Tom Banks, 14. Henry Speight, 13. Tevita Kuridrani, 12. Kyle Godwin, 11. Aidan Toua, 10. Wharenui Hawera, 9. Joe Powell, 8. Jordan Smiler, 7. Chris Alcock, 6. Scott Fardy, 5. Sam Carter, 4. Rory Arnold, 3. Allan Alaalatoa, 2. Josh Mann-Rea, 1. Nic Mayhew. Reserves: 16. Robbie Abel, 17. Faalelei Sione, 18. Les Leuluaialii-Makin, 19. Tom Staniforth, 20. Jarrad Butler, 21. De Wet Roos, 22. Andrew Muirhead, 23. Nigel Ah Wong.

Rebels team: 15. Reece Hodge, 14. Sefa Naivalu, 13. Tom English, 12. Mitch Inman, 11. Marika Koroibete, 10. Ben Volavola, 9. Nic Sirzaker, 8. Amanaki Mafi, 7. Colby Faingaa, 6. Hugh Sinclair, 5. Lopeti Timani, 4. Steve Cummins, 3. Tyrel Lomax. 2. James Hanson, 1. Toby Smith. Reserves: 16. Siliva Siliva, 17. Cruze Ah Nau, 18. Laurie Weeks, 19. Culum Retallick, 20. Will Miller, 21. Ben Meehan, 22. Jackson Garden-Bachop, 23. Jonah Placid.