'It's a line in the sand': Warning to dropped Wallabies hooker

Brumbies coach Dan McKellar has encouraged the NSW Waratahs to have faith in Australian talent in their search for a new coach.

And he has tipped his out-of-favour hooker Folau Fainga'a to have "plenty of fire in the belly" as the Brumbies prepare for the Waratahs' response on Friday, just days after coach Rob Penney was axed.

With the unbeaten Reds in the box seat to earn Super Rugby AU grand final hosting rights, the Brumbies cannot afford to slip up against the winless Waratahs.

"They'll have a bit more emotion and motivation on board this week no doubt," McKellar said.

"Other codes and sports will talk about when a coach is unfortunately sacked, teams really front up the next week."

Penney was booted less than two seasons into the job, despite a spate of injuries to key players and a long list of departures before and after he arrived, as the club tightened their recruitment purse strings.

Assistant coaches Jason Gilmore and Chris Whitaker will lead the Waratahs at the SCG, while Australian women's sevens coach John Manenti is in the frame to take the job full time.

McKellar admitted Penney appeared to have received a rough hand but said the Waratahs' job should still be appealing, particularly to an emerging Australian coach.

"There's a lot of very, very good coaches in Australia," he said.

"And coaches are no different to players; until you give them a chance or opportunity you'll never know."

Wallabies winger Tom Wright (knee) will play his first game of the season for the Brumbies while Jake Gordon (ankle) will return to captain the Waratahs.

Fainga'a will start for the Brumbies after Australia coach Dave Rennie left him out of a 40-man Wallabies squad that will gather next month.

"It's a little bit of fire in the belly I suppose and (he needs to) understand it's not the final squad for the Bledisloe or Rugby Championship," McKellar said of his 16-test hooker.

"It's a line in the sand there and I'm sure Dave's given them good feedback and (Fainga'a) will have that bit of competitive edge there and want to prove a point."

Meanwhile, Australian sevens talents Lewis Holland and Jeral Skelton have been named on the bench for the Melbourne Rebels, who will host the Reds on Saturday.

Reds winger Suliasi Vunivalu (hamstring) will not play, with Bryce Hegarty promoted to fullback, Hamish Stewart back in the centres for his 50th Super Rugby game and Jock Campbell and Jordan Petaia sent to the wings.

- Murray Wenzel