Brumbies duo Christian Lealiifano (shoulder) and Scott Sio (adductor) have been ruled out of the first Test against South Africa, while Rob Valetini is returning home after the Wallabies squad was trimmed on Wednesday night.

News of the injury and selection decisions came after wingers Henry Speight and Toni Pulu committed to playing in the John I Dent Cup on Saturday to put themselves back on the Wallabies radar.

Fourteen Brumbies will return to the premier Canberra club competition this weekend and Valetini could join them after Wallabies staff said he had been cleared for first-grade duties.

Speight to play for the Gungahlin Eagles and Pulu to suit up for the Easts.

Speight, Pulu and Pete Samu flew to Sydney earlier this week to train with a Wallabies extended squad after missing selection in the team to play in Johannesburg on Sunday morning.

Samu is still trying to overcome the hamstring injury which prematurely ended his Brumbies season and the Wallabies are closely monitoring the two-time Super Rugby champion's fitness.

Speight and Pulu are considered to be on the fringes of the Test squad, but their World Cup chances are still alive after strong campaigns in Canberra.

The Brumbies had the biggest representation of any Australian side in the Wallabies squad, with 10 players in South Africa for the first Test of the year.

Rugby Australia director of rugby Scott Johnson said the Wallabies would manage player workloads for Brumbies players given they were the only ones to play in the Super Rugby finals.

"We're taking into considerations some things like where they are at health wise," Johnson said.

"Some have shown some war wounds so ... we're taking a longer view of some purely on the fact that some have had big seasons some may have slight ailments that we think aren't quite right to go.

"You can't take them into a Test match if you're not sure so we'll go who's best on form, how do the combinations work, we need to see a couple of things.

"The team is there to win the Test match. In the Brumbies case there are guys who may miss because they may be battered and bruised. It's important they get an opportunity to see how we play."

However, that may impact their World Cup chances given there are just five matches before the opening game of the Wallabies' tournament on September 21, leaving minimal time for players to impress.

Folau Faingaa, Allan Alaalatoa and James Slipper are expected to get their chance against the Springboks and Tom Banks is hopeful of winning the battle for the vacant fullback role.

BRUMBIES NEWS

"I've been really impressed with [Banks'] form, just his application in and around training and putting his hand up as well," Lealiifano said.

"So, I guess we're not selectors but I definitely feel he's ready and hopefully he does get a crack.

"I think he's been in outstanding form all year, he's tough, he rips in at training and he just goes about his work, which is something that we admire and love seeing. Hopefully he gets rewarded for that."

Speight and Pulu are taking a different path to try to win a gold jersey.

Speight will team up with Mack Hansen at the Eagles for a top of the table clash against Royals, who will boast Andy Muirhead and Connal McInerney.

Vunipola Fifita, Ryan Lonergan, Len Ikitau, Darcy Swain and Noah Lolesio and Lachlan Lonergan will play for the Vikings.

Tom Wright (Wests), Blake Enever (Easts) and Nick Frost and Matt Lucas (Queanbeyan) will also get game time this weekend.

Pulu moved from New Zealand to Australia this year in the hope of earning a call up for the Wallabies' World Cup campaign.

Speight has finished his Brumbies career and will join the Queensland Reds next year, but is staying in Canberra as he awaits the birth of his first child.

"I wouldn't have committed to stay in Australia if the Wallabies wasn't still the ultimate goal," Speight said after being knocked out of the Super Rugby finals.

"I still really feel I can push for that. It's beyond my control right now ...Seeing guys like Sekope Kepu having his sons watch him play, that would be awesome if I could do that.

"It is still the highest honour for me and if it wasn't, I'd be kidding myself staying in Australia."

JOHN I DENT CUP ROUND 16

Saturday: Queanbeyan Whites v Easts at Campese Field, 3.05pm; Royals v Gungahlin Eagles at Phillip Enclosed, 3.05pm; Tuggeranong Vikings v Wests at Viking Park, 3.25pm.

BRUMBIES IN ACTION

Tuggeranong: Noah Lolesio, Vunipola Fifita, Darcy Swain, Ryan Lonergan, Lachlan Lonergan, Len Ikitau.

Royals: Connal McInerney, Andy Muirhead.

Gungahlin: Henry Speight, Mack Hansen.

Wests: Tom Wright.

Easts: Toni Pulu, Blake Enever.

Queanbeyan: Nick Frost, Matt Lucas.