The Brumbies could be without both Allan Alaalatoa and Tom Ross for Friday week's clash with the Western Force at Canberra Stadium, with the latter now under an injury cloud with a knee issue.

Ross came off early in the Brumbies' heartbreaking 40-38 loss to the Queensland Reds on Saturday night, with his strapped left knee to be assessed early this week.

With Alaalatoa already out with a three-match suspension, a negative outcome for Ross could make way for little-known rookie Holz to fill the void left in Brumbies' front-row at tighthead prop.

It means 21-year-old Holz would go from playing colts in Sydney to starting for the Brumbies in less than 12 months.

"It's something you never want to see happen in terms of injuries but if I'm thrown in there, I'll give it my best and I still have a long way to go," Holz said.

"Something everyone can expect is that I'll give my most out there. That's all anyone can ask of me, so that's what I'm going to do if I get that opportunity.

"I'll give it my best crack and do what I can for the team."

MORE CANBERRA SPORT

Dan McKellar's outfit is also sweating on the fitness of starting prop Scott Sio after he trundled off bracing his arm in the 46^th minute, while Tom Cusack finished the game with ice on his shoulder. Both will have scans early this week.

It's also a hit to their leadership stocks, with potentially three key players now out.

But on the bright side, James Slipper is a chance to return after the bye round for the Force clash.

Ross' early exit from the front-row saw Holz play 32 minutes off the bench in his Super Rugby AU debut.

He made one carry, six tackles and won a turnover as the Brumbies fell to their first loss of the season.

Nevertheless, it was a dream come true for Holz who made his way to the reigning champions this year via the Shute Shield.

"It's something I've dreamed about for years. The Brumbies are a very special club, to get the opportunity to come down here and receive my first cap is so special," Holz said.

"It wasn't the result we wanted, it was really tough out there and definitely a big learning curve for me. But to do it in front of a great crowd, friends and family was unreal.

"It's a big step up, the speed of the game is massive. I was blowing out there, it was tough. That will come, having such an experienced team around me is so helpful.

"When I'm out of position or something like that, which is obviously going to happen the first time playing for a team, I've always got those guys to help me into line which is awesome to have.

"It was longer than expected, but it was good to get out there and soak up the atmosphere."