The return of the prop duo comes at a crucial time for the Brumbies as they look to bounce back from a subpar 24-22 win over the struggling NSW Waratahs at the Sydney Cricket Ground on Friday night.

The Brumbies finished with 13 men and Will Harrison had a chance to level the scores long after the 80-minute mark with a conversion from the sideline but his attempt faded, moments after James Ramm scored to ignite hopes of a shock upset against the reigning champions.

Brumbies coach Dan McKellar and captain Nic White conceded there were some dejected figures in the sheds after the narrow win, having looked a shadow of themselves against a Waratahs outfit hellbent on redemption in their first outing after coach Rob Penney was sacked.

"The boys are pretty down to be honest," McKellar said.

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"We need to remember we won, but we also need to remember we were well off the pace. We did some really good things in attack and scored a couple of nice tries, but defensively we had no sting and they did.

"Effort areas and physical intent, normally things we pride ourselves on, we were a little bit off. We'll be well on next week. We can sit here now and understand we walk away with four points, and go onwards and upwards."

The looming return of Alaalatoa from suspension and Sio from an elbow injury will be a huge boost against a formidable Reds outfit in a game that could define the finals race.

"They're world-class front-rowers," McKellar said.

"[Harry Lloyd], really happy with Freddy Kaihea from our academy, he stumped up and fronted up really well in the last couple of scrums there, big Sefo [Kautai] as well.

"But it's hard to replace world class experienced front-rowers, so it'll be good to have them back."

Brumbies captain Nic White is bracing for a "ruthless" review after the visitors, who showed glimpses of class with tries to Tom Wright, Tom Banks, Andy Muirhead and Folau Fainga'a, left plenty to be desired from their own assessment.

"There's a lot of guys hurting down there, it almost feels like a loss. I've just had to remind guys we did win," White said.

"If you were going to be asked on Monday if we were going to win on the weekend, we'd take it. It's good to be into the review on Monday and have that really ruthless and honest review, knowing we still got the result."

They did so at a venue steeped in rich sporting history. Think Steve Waugh's last ball century, Michael Clarke's triple, Brian Lara's double, Ashes whitewashes, rugby league grand finals and countless slugfests for your Saturdays and Sundays.

But a Waratahs victory would have been among the most magical moments to have taken place on the hallowed turf given the turmoil the club finds itself in.

Rory Scott was given a yellow card with six minutes left, and Tom Cusack followed after the 80-minute mark with red, giving the Waratahs a scrum metres out at the death. Ramm scored off the back off it to slice the deficit to two before Harrison's conversion went astray.

The Brumbies were bracing for a Waratahs backlash after Penney was axed and made to feel like a scapegoat for a club facing an alarming decline.

Few fans made their way through the turnstiles, and some of those who did posted on social media they were "here for the boys, not for the board" with a middle finger emoji to boot. Pressure is mounting on the NSWRU board, with fans and stakeholders demanding answers.

The Waratahs came in as rank outsiders and Jason Gilmore and Chris Whitaker were hoping for signs of life in their first game in charge as Penney's interim replacements.

They got just that, but why it took a coach getting sacked for the Waratahs to begin to turn things around is anyone's guess.

"It's been an emotional week," Waratahs captain Jake Gordon said.

"We spoke about it in the sheds, putting in a really good effort for Rob. I can't answer why it's happened like that.

"We also got a few guys back. We had a very clear game plan this week and we stuck to it, that was the difference."

The finals-bound Brumbies will now turn their attention to a date with the Reds in a match that could ultimately determined the minor premiership.

AT A GLANCE

Super Rugby AU round seven: ACT BRUMBIES 24 (Tom Banks, Tom Wright, Andy Muirhead, Folau Fainga'a tries; Noah Lolesio 2 conversions) bt NSW WARATAHS 22 (Harry Johnson-Holmes, Will Harrison, James Ramm tries; Harrison 2 conversions; Harrison penalty) at Sydney Cricket Ground.