The Wallabies' forward stocks continue to take a battering with key prop Sekope Kepu joining David Pocock on the sidelines ahead of Australia's return Rugby Championship match against New Zealand in Auckland on Saturday.
Captain Pocock was ruled out for the remainder of the competition after undergoing keyhole surgery on his right knee and in a further blow for the Wallabies Kepu was scratched late Tuesday with a knee injury.
The powerful prop sustained a grade two strain to the medial ligament of his right knee in training on Tuesday, an injury that can typically put a player out of action for a month.
It was another cruel blow for the struggling Wallabies after confirmation Pocock would miss up to three months, also putting him in doubt for the Wallabies' November spring tour.
The surgery was required after Pocock damaged the articular cartilage in last Saturday's match with New Zealand in Sydney.
Pocock took over the captaincy at the start of the international season after first-choice skipper James Horwill was ruled out of the four June Tests and the Rugby Championship with a hamstring injury.
Halfback Will Genia, who captained Australia once before against the United States in last year's World Cup, has been confirmed as the new skipper, starting with Saturday's clash with New Zealand in Auckland.
He is the fourth man to hold the position in just over 12 months, following Rocky Elsom, Horwill, and Pocock.
While without the direct-playing Pocock, the chastened Wallabies are still intent on showing more fire and aggression at the breakdown in Auckland.
Outplayed in the 27-19 loss in Sydney last weekend, Australia have targeted an improvement in the contact area after conceding too many turnovers in that game.
"We just let them in to our breakdown and turned over our ball a bit easy," Wallabies lock Sitaleki Timani said.
"I think the thing we need to do is don't be nice to them at the breakdown.
"Try to get them off our ball and try and get quick ball to the backs to do their job.
"Watching the game, they just lay all over our ball and we didn't really do too much about it."
Timani backed the new concussion test introduced last weekend after he was one of its first cases, following a clash with teammate Anthony Faingaa.
"It's really good because you can't really tell if you can still carry on playing when you've got concussion on the field," Timani said.
"I think it's better to bring you off and do a little test to finalise that you will be alright to play again or stay off the field."