"Pop up to the office and let's have a chat."

So upstairs the Brumbies flanker went to greet a coach on the hunt for a new captain after Allan Alaalatoa was hit with a three-game ban for a high shot.

Cusack says McKellar's message was simple: "You'll be skippering the side, just bring great calmness and good direction".

The 28-year-old will become the third ACT junior to captain the Brumbies when he leads them into a Super Rugby AU showdown with the Queensland Reds at Canberra Stadium on Saturday night.

MORE RUGBY UNION

Cusack joins George Gregan and Matt Giteau as the only Canberra products to lead Australia's most successful top flight rugby union club, and he becomes the 18^th captain in the club's 25-year history.

"I've grown up supporting this side, I've grown up with the trials and tribulations of watching the Brumbies play footy," Cusack said.

"I never thought I would even play let alone having the C next to my name. I'm really happy to be back in the side, back starting, playing alongside some quality players.

"It's good to have [scrumhalf Nic White] out there running his race and a lot of good leaders who know how to control a game, so it's going to be somewhat of a breeze having great support through the whole team.

"To have that confidence from the head coach to know I'm doing the right thing when I do get out there to be able to control a game and to be able to have the support of the group, it's pretty special to know you're doing the right thing."

The significance of handing the captaincy reins to a local junior is not lost on McKellar, who has for years been determined to strengthen allegiances between the Brumbies and junior pathways.

"It's really special for Tommy and his family, a local Canberra family, so I know they'll all be really proud of him on Saturday night when he leads the team out," McKellar said.

"It's a sign of our investment in local talent and the little boy who wants to play for the Brumbies and one day might get the chance to lead them out if you work hard and are nice and resilient like Tommy Cusack has been over a long period.

"He's a genuine leader, he has done a really good job for us in the last 25 minutes of games. Very calm, composed. Good story as well, isn't it? A Marist boy.

"He has captained a lot of teams in the past, Tommy, he knows what leadership is all about. I just thought he deserved the opportunity."

The opportunity doubles as a major challenge for Cusack and the Brumbies in a top of the table clash against the biggest threat to their domestic throne.

Folau Fainga'a returns to the starting XV at hooker after overcoming a toe injury. He could have played at a push last week, but was held back for a battle with in-form Reds rake Alex Mafi and Brandon Paenga-Amosa.

Fainga'a's return is a timely one following the loss of Connal McInerney, who underwent surgery on a broken fibula on Tuesday which could spell the end of his Super Rugby AU season.

The 25-year-old will pack down in the Brumbies front-row alongside Wallabies star Scott Sio and local junior Tom Ross, who makes his first Super Rugby start in the absence of Alaalatoa.

"He's raring to go, he'll have a point to prove, Folau," McKellar said.

"He's got a big job to do around the set piece, and his left shoulder is going to be the most important body part out there on Saturday evening at scrum time. He's ready to go."

Ross' elevation into the starting line-up opens the door for Archer Holz to make his Super Rugby debut with the 21-year-old boasting an imposing 128 kilogram, 189 centimetre frame.

"He's a big body, he's a big boy. I watched him play for Easts last year in the Shute Shield, he has a real thirst for scrummaging, natural physicality with his game as well," McKellar said.

"I'm really pleased for Archer and his family as well. He got a head knock in pre-season which hung around for a little bit longer than we would have liked.

"But he has worked hard and times have changed really quickly. He has a chance to make his debut on Saturday evening."

SUPER RUGBY AU ROUND FOUR

Saturday: ACT Brumbies v Queensland Reds at Canberra Stadium, 7.45pm. Broadcast: Live on Gem and Stan Sport. Tickets from Ticketek.

ACT Brumbies team: 1. Scott Sio, 2. Folau Fainga'a, 3. Tom Ross, 4. Darcy Swain, 5. Cadeyrn Neville, 6. Rob Valetini, 7. Tom Cusack (c), 8. Pete Samu, 9. Nic White, 10. Noah Lolesio, 11. Mack Hansen, 12. Irae Simone, 13. Len Ikitau, 14. Andy Muirhead, 15. Tom Banks. Replacements: 16. Lachlan Lonergan, 17. Harry Lloyd, 18. Archer Holz, 19. Nick Frost, 20. Jahrome Brown, 21. Ryan Lonergan, 22. Reesjan Pasitoa, 23. Issak Fines-Leleiwasa.

Queensland Reds team: 1. Dane Zander, 2. Alex Mafi, 3. Taniela Tupou, 4. Angus Blyth, 5. Lukhan Salakaia-Loto, 6. Angus Scott-Young, 7. Fraser McReight, 8. Harry Wilson, 9. Tate McDermott, 10. James O'Connor (c), 11. Filipo Daugunu, 12. Hunter Paisami, 13. Jordan Petaia, 14. Suliasi Vunivalu, 15. Jock Campbell. Replacements: 16. Brandon Paenga-Amosa, 17. Harry Hoopert, 18. Zane Nonggorr, 19. Ryan Smith, 20. Seru Uru, 21. Moses Sorovi, 22. Bryce Hegarty, 23. Josh Flook.

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