Star flanker David Pocock is on track to play in the Brumbies' Super Rugby qualifying final against the Stormers in Cape Town, but a question mark lingers over fellow Wallaby Matt Toomua.
Pocock missed the entire second half of Saturday's loss to the Crusaders at GIO Stadium after suffering a knock to the head and failing a concussion test.
He flew with the team to South Africa on Monday and participated in their first training session for the sudden-death match on Saturday (Sunday am AEST).
"So he's on track to play," coach Stephen Larkham said.
"He'll certainly be available for selection at this stage.
"But every day he's got to tick a box, so he could fall back a day and he could miss the game."
Larkham was just as optimistic about playmaker Toomua, even though he pulled up sore on Tuesday following his 28-minute stint off the bench on Saturday.
That was just his second game in eight matches following two separate ankle injuries.
"He was limping around today so he's in a bit of pain," added Larkham.
"Coming back from a syndesmosis ... everything is cleared medically, it's just whether he feels good tomorrow, which I suspect he will."
The Brumbies are preparing for another physical game against the Stormers, to whom they lost 25-24 at DHL Newlands in May.
A missed Christian Lealiifano kick proved the difference and left the No.10 devastated.
But he said on Tuesday he wasn't out to seek redemption.
"I hadn't thought about that kick until now - so, thanks," said Lealiifano with a laugh.
"I just think it's a fantastic opportunity we have here to play some finals footy and progress."
Larkham said he had every confidence in Lealiifano and lauded his resolve to improve.
"Particularly since that miss, Christian's spent more time at training practising his conversions and penalty kicks," the coach said.
"I think we've seen a bit of a turnaround over the last month in his goal-kicking - last weekend he kicked really well."
Nevertheless, Larkham said his side would take extra care with their option-taking when awarded penalties against the Stormers, given a semi-finals berth is on the line.
The Brumbies have lost four times this season by three points or less.
"We'll be treating it like a Test match," he said.
"We'll be very careful with the decisions that we take at penalty times.
"I'm sure (captain Stephen Moore) will make good decisions on the night as he's done over the last month."