Something separates a rivalry like this from the underdog mentality which fuels the Brumbies during Tah week, or the rich history of grand final spectacles against the Canterbury Crusaders.

A unique history is fuelling the Brumbies and the Western Force ahead of a Super Rugby AU showdown at Leichhardt Oval on Saturday night.

When the Force took their first steps into a brave new world then known as Super 14 back in 2006, it was the Brumbies there to spoil the party in front of more than 30,000 fans in Perth.

Matt Giteau left Canberra to head west in 2007 before a homecoming a few years later. The Force denied the Brumbies a slice of history when they won the world club 10s final in Mauritius in 2016.

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Then it was the Brumbies winning a game that ultimately brought down the curtain on the Force's time in Super Rugby in 2017.

So it is perhaps fitting Western Australia's on-field revival in the nation's premier domestic competition is led by former Canberra Vikings and Tuggeranong coach Tim Sampson.

"That's what they're carrying, they have a point to prove, that they want to stay," Alaalatoa said.

"They have a whole state they are representing, a state that wasn't included in Super Rugby over the past couple of years. It's great to have them back in.

"For me, the biggest eye opener was playing the Test over there in Perth and seeing how much they love their rugby over there. For them, being back in the comp is awesome. Hopefully they remain in the comp going forward."

The Brumbies have traditionally been the Force's toughest interstate opponent, having won 13 of 18 encounters against the Perth-based club.

Now the Force have the added motivation to secure their first win of the season after fading after fast starts in consecutive matches.

Even now they are intrinsically linked by their XVs, with Harry Lloyd returning to the visitors' bench and ex-Brumby Angus Wagner packing down opposite Alaalatoa in the scrum.

As debate rages about the viability of five teams on the national domestic scene, with Rugby Australia determined to build a future with all five included, one thing that cannot be understated is the opportunities it creates for players like Wagner.

"It's definitely exciting to see him get his opportunity, someone here that was probably the sixth or seventh prop but always willing to learn and was always out there doing his extras and working hard," Alaalatoa said.

"He will definitely be up for it, so are we. They've been playing some great footy, and all you need to do is slip up once and they're over the line.

"You can't give them a sniff early, because as we've seen, they definitely take their opportunities. This game is not a game we are taking lightly. The boys are ready for it.

"They're always up for the game. A team who has come back into the Super Rugby fold, they definitely have a point to prove. They showed that in different patches of both games.

"For us, it's focusing on our role but understanding their threats. They definitely have a point to prove, and we need to ride the wave early."

SUPER RUGBY AU ROUND FOUR

Saturday: Western Force v ACT Brumbies at Leichhardt Oval, 7.15pm.

Brumbies: 1. Scott Sio, 2. Folau Fainga'a, 3. Allan Alaalatoa, 4. Murray Douglas, 5. Nick Frost, 6. Rob Valetini, 7. Will Miller, 8. Pete Samu, 9. Joe Powell, 10. Bayley Kuenzle, 11. Tom Wright, 12. Irae Simone, 13. Tevita Kuridrani, 14. Solomone Kata, 15. Tom Banks. Reserves: 16. Connal McInerney, 17. Harry Lloyd, 18. James Slipper, 19. Ben Hyne, 20. Lachlan McCaffrey, 21. Issak Fines, 22. Mack Hansen, 23. Andy Muirhead.

Force: 15. Jack McGregor, 14. Byron Ralston, 13. Marcel Brache, 12. Henry Taefu, 11. Brad Lacey, 10. Jono Lance, 9. Nick Frisby, 8. Brynard Stander, 7. Tevin Ferris, 6. Henry Stowers, 5. Fergus Lee-Warner, 4. Jeremy Thrush (capt), 3. Kieran Longbottom, 2. Feleti Kaitu'u, 1. Angus Wagner. Reserves: 16. Andrew Ready, 17. Chris Heiberg, 18. Tom Sheminant, 19. Ollie Atkins, 20. Ollie Callan, 21. Jacob Abel, 22. Richard Kahui, 23. Kyle Godwin.