The Brumbies face a last-round dangerous test against the unpredictable Western Force at Canberra Stadium on Friday night.

If they beat the controversy-stricken Force with a bonus point they will advance to the finals irrespective of any other results.

However, their play-off chances will be largely determined by how the NSW Waratahs perform against the Auckland Blues on Friday night.

Only one Australian team will be able to make the finals, with the Brumbies in the box seat to finish at the top of the conference.

The Brumbies or Waratahs would have to match the firepower of New Zealand teams in the finals and prop Scott Sio says regular-season results will count for nothing when the play-offs begin.

A disastrous weekend for Australian teams led to a combined 203-63 landslide in trans-Tasman battles across four games, including the Brumbies losing to the Blues, the Waratahs stumbling against the Wellington Hurricanes, the Queensland Reds flopping against the Waikato Chiefs and the Melbourne Rebels being blown away by the Canterbury Crusaders.

The Brumbies beat the Hurricanes in the opening game of the season but Australian sides have won just three of 24 clashes against New Zealand teams.

If the ladder remains unchanged the Brumbies would play the Crusaders in Canberra in the first week of the finals.

"You're going to have those weekends and unfortunately it was the Aussie teams that suffered [last weekend]," said Brumbies prop Scott Sio.

"It's a week by week prospect in this competition, and we can definitely turn everything around in a week.

"That goes for all the teams moving forward. Everyone just has to take the weekend for what it was and take what they can from there to keep moving forward.

"At the end of the day you have to beat all of the best teams to win this competition, so it doesn't matter who you play in the finals. It's just about whether you turn up."

The Brumbies suffered a blow on Monday when winger Joe Tomane was ruled out for the rest of the year after suffering two leg fractures, while David Pocock, Jordan Smiler and Scott Fardy will be monitored this week.

Sio conceded the Brumbies' "effort areas" weren't where they needed to be in a disappointing 40-15 loss to the Blues that put their finals hopes in jeopardy.

But he was confident the Brumbies could get their campaign back on track against the Force.

The Force have struggled through the final weeks of the season, with the club sacking coach Michael Foley and some star players caught up in an off-field alcohol-fuelled controversy which led to Dane Haylett-Petty and Pek Cowan both being fined $5000.

The Brumbies are refusing to take the Force lightly, despite their struggles and just two wins this year.

"We get another chance now to do the job ourselves and put ourselves in a good spot to keep going," said Brumbies' back-rower Jarrad Butler.

"We're still in it but we've got a massive task ahead of us [against the Force].

"Going into finals you need to build all of the momentum that you can, and this one in particular, you want to get the ball rolling after a pretty disappointing result [last weekend].

"Everyone will be pretty motivated to get this last game behind us and play well, and then to hopefully roll through to finals in the best sort of form we can. If that doesn't motivate guys I don't know what will. But everyone is pretty excited to get back on the right side."

SUPER RUGBY ROUND 17

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

BRUMBIES FINALS SCENARIOS

• If the Waratahs lose to the Blues by more than seven points the Brumbies will advance to the play-offs regardless of their result against the Force.
• If the Waratahs lose to the Blues by fewer than seven points the Brumbies will need to either beat the Force or lose by fewer than seven points as well.
• If the Waratahs beat the Blues the Brumbies need to beat the Force.
• If the Waratahs secure a bonus-point triumph the Brumbies need to do the same against the Force.