Brumbies duo Slipper and Pete Samu will miss the competition decider against the Queensland Reds at Lang Park on Saturday night.

Slipper's absence is the hard-luck story of grand final week. It would have marked a return home to Queensland, where he could have played a decider in front of family and friends.

Instead he misses out due to injury in a cruel twist of fate. The 100-Test prop also missed a final on home soil when he was playing for the Reds in 2011, when he succumbed to an ankle injury.

Now Sio will pack down in a starting front-row featuring Allan Alaalatoa and Lachie Lonergan, with Harry Lloyd providing cover at loosehead prop off the bench.

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"Obviously gutted for him," Sio said.

"He would have loved to play in front of family and friends in a grand final up there [in Brisbane] where he represented many a team on many occasions there.

"I understand we've got to do the job for him and the guys who are unfortunately missing out this weekend, and making sure we bring back some silverware for them."

Brumbies coach Dan McKellar waited until the 11^th hour to make a call on the injured pair, adamant he wanted to give them as long as possible to prove their fitness.

He was ultimately forced to reshuffle his forward pack, with Rob Valetini moving to No. 8, Nick Frost to flanker and Henry Stowers to the bench for a Brumbies debut.

McKellar is hopeful the pair will feature in Super Rugby Trans-Tasman, though he is still waiting to hear how long they may spend on the sidelines.

"We don't know the exact time frames yet. It's going to be weeks, certainly not months," McKellar said.

"Shattered for them, shattered for any of the players that miss out on selection. Obviously those two have played a big role in getting us here, so it creates a really good opportunity, and we'll just back the next person to stand up and do the job.

"We gave them as much time as possible. They play with injury and they play tough, both of them can do that.

"But when it's a risk of further injury or threatening to leave them being on the bench or on the sideline for months on end, we certainly weren't going to do that."

Sio's call up throws him into a battle with an imposing Reds pack spearheaded by Taniela Tupou, who continues to emerge as one of world rugby's best props.

But it's a challenge Sio is relishing as the Brumbies take on the star-studded Reds.

"He has been one of the top performers now for a couple of years, and he is one of their go-to men in their team up there," Sio said.

"They're a team of 23 at the end of the day, we've got to account for everyone and make sure we all do our role individually and make sure we all do our roles individually to make sure the team has success.

"It's always a big challenge, they're a great set piece team and they thrive on it. We know it's going to be a big day for us up there, we've got to front up and play Brumbies rugby for 80 minutes."

SUPER RUGBY AU FINAL

Saturday: Queensland Reds v ACT Brumbies at Lang Park, 7.45pm. Broadcast: Live on Stan Sport and 9Gem. Tickets from Ticketek.

ACT Brumbies squad: 1. Scott Sio, 2. Lachlan Lonergan, 3. Allan Alaalatoa (c), 4. Darcy Swain, 5. Cadeyrn Neville, 6. Nick Frost, 7. Rory Scott, 8. Rob Valetini, 9. Nic White, 10. Noah Lolesio, 11. Tom Wright, 12. Irae Simone, 13. Len Ikitau, 14. Andy Muirhead, 15. Tom Banks. Replacements: 16. Folau Fainga'a, 17. Harry Lloyd, 18. Tom Ross, 19. Henry Stowers, 20. Luke Reimer, 21. Ryan Lonergan, 22. Reesjan Pasitoa, 23. Mack Hansen.

Queensland Reds squad: 1. Feao Fotuaika, 2. Brandon Paenga-Amosa, 3. Taniela Tupou, 4. Ryan Smith, 5. Lukhan Salakaia-Loto, 6. Angus Scott-Young, 7. Fraser McReight, 8. Harry Wilson, 9. Tate McDermott, 10. James O'Connor (c), 11. Jock Campbell, 12. Hamish Stewart, 13. Josh Flook, 14. Jordan Petaia, 15. Bryce Hegarty. Replacements: 16. Alex Mafi, 17. Dane Zander, 18. Zane Nonggorr, 19. Seru Uru, 20. Liam Wright, 21. Kalani Thomas, 22. Isaac Henry, 23. Filipo Daugunu.

*The Brumbies are offering a package for fans including a charter flight to and from Brisbane, a ticket to the final, and one night's accommodation. Secure your seat here.

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