"I've got no idea, I'm not into those sort of stats," McKellar responded without a smirk.

"Plenty. It's generally the case, it's a physical game. We wouldn't have it any other way to be honest, it's good that everyone understands they'll get their opportunity and when it's their time to contribute they've just got to be ready to go."

The Brumbies coach has had to reach into the depths of his playing roster again this week ahead of Saturday's preliminary final against the Western Force.

Flanker Luke Reimer is on the bench after two strong games for Wests at local level, and has the rare opportunity to make his debut in a final should he be required this weekend.

It's hardly ideal for McKellar to be calling upon first starters when the Brumbies' season is on the line, but he didn't hesitate to call potentially blood another debutant.

"Unfortunately sometimes it's through injuries that players get opportunity and exposure - it's good to see Lukey get his chance, he's been nice and patient and worked hard and he's performed really well for his club over the first couple of weeks," McKellar said.

"He's a traditional seven. He's pretty physical certainly on the ground, he's a genuine poacher, I think he got five or six turnovers last week for Wests against Tuggeranong.

"As a schoolboy he had a really good career, I think he won the Golden Boot in the Test match against New Zealand which is a pretty prestigious award.

"He's been here for a couple of years in our program now. He's worked hard, and ready to step up at Super Rugby level.

"Whether it's a semi-final, round one, round two, trial game whatever it is, they know their job within our systems here and they've just got to go out and do it."

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McKellar has been forced into several other changes for the Force clash, reworking his starting forward pack.

James Tucker's rib injury has forced him out of action, meaning Rob Valetini will start at blindside flanker. Rory Scott retains his spot at openside while Pete Samu comes back in at number eight.

Will Miller remains sidelined with a shoulder and neck complaint, while Tom Cusack is still nursing a groin injury.

Wallabies veteran James Slipper will start at loosehead prop as Scott Sio drops back to the bench, Nic White starts at scrumhalf while Irae Simone returns at inside centre after shaking off a niggling leg injury.

McKellar's troops have had the luxury of a week off thanks to a final-round bye, while the Force are on a stunning three-match winning run which has propelled them into third spot.

Last weekend's narrow win over the previously unbeaten Queensland Reds followed back-to-back one-point triumphs against the NSW Waratahs, and Melbourne Rebels.

"They're the only team to have knocked off the Reds this year and they've got some momentum at the moment," McKellar said.

"Momentum and confidence allows you to probably throw a pass that you might not necessarily throw, and just take that chance and back your execution.

"[Tomas] Cubelli's been a threat in the last couple of weeks and we know Tomas very well here. He's started to come into his game a little bit more.

Saturday's preliminary final, which offers the winner a shot in next weekend's decider against the Queensland Reds in Brisbane, is the first taste of post-season football the Force have had since joining Super Rugby in 2006.

The Brumbies are no strangers to finals football and are desperate to defend their title, but McKellar said the disparity in playoff experience between the two sides would count for little.

"We've got plenty of players that have got experience in big games but I think they're probably the same, they've got guys in there that have won World Cups and played a lot Test match footy," McKellar said.

"At the end of the day it comes down to the team that turns up with the greatest intent, wants to win the collision, dominate the collision and who takes their opportunity, that's who generally wins semi-finals. We won't be reading too much into what's happened in the past, it's knockout footy."