Rory Arnold admits he is wary of Australia's next generation of second-rowers after coach Michael Cheika dumped Kane Douglas from his squad for Saturday's Test against Argentina to make way for another young gun.
Lukhan Tui is in line for a potential debut at Canberra's GIO Stadium with Douglas, his Queensland Reds teammate, sent back to the National Rugby Championship in search of game time.
Douglas was lured back to Australian rugby at great expense two years ago and started in the 2015 World Cup final for the Wallabies at a time when their lock stocks were suffering.
But Cheika is building plenty of depth after bringing through Arnold and Adam Coleman last year, while he also gave Izack Rodda his first cap in last month's Bledisloe Cup defeat in Dunedin.
"I'm looking over my shoulder (at) those young bucks coming through pushing me for selection," Arnold told reporters in Canberra on Monday.
"Two or three years ago that second-row spot, we didn't have much depth in Australia. Look at it now."
Tui, 20, has recently recovered from knee surgery and was called up for the first time by Cheika in June but is yet to make his Wallabies debut.
Rodda, 21, made his first appearance for Australia in last month's Bledisloe Cup defeat in Dunedin.
Both play with Douglas at the Reds and have overtaken him not only at Super Rugby level but now the Test pecking order as well.
It seems a long road back for the 28-year-old Douglas, who has not made a single Test appearance this year.
Arnold said players were left with a "sour taste" from Saturday's 23-23 draw with South Africa, which has left the Wallabies with a poor record of just eight wins from 21 games since the World Cup.
"We reviewed it and we had a number of opportunities where we could have held out and won that game but we just slipped up a bit there with just our details," he said.
Argentina will be no pushover after rattling New Zealand at the weekend, taking the lead early in the second half before succumbing 39-22 to the world champions.
"It just proves how good they can be when they're playing good footy," Arnold said.
Saturday's clash is Australia's first in Canberra since 2010, while Argentina haven't played there for 17 years.
The Wallabies will have former skipper Stephen Moore back on deck after he sat out last week for the birth of his third child, with with hooker Tolu Latu and injured winger Dane Haylett-Petty (biceps) dropping out of the squad.
WALLABIES SQUAD:
FORWARDS: Allan Alaalatoa, Rory Arnold, Adam Coleman, Jack Dempsey, Tetera Faulkner, Ned Hanigan, Michael Hooper (capt), Sekope Kepu, Adam Korczyk, Sean McMahon, Stephen Moore, Tatafu Polota-Nau, Tom Robertson, Izack Rodda, Rob Simmons, Scott Sio, Lopeti Timani, Lukhan Tui, Jordan Uelese.
BACKS: Kurtley Beale, Israel Folau, Bernard Foley, Will Genia, Reece Hodge, Samu Kerevi, Marika Koroibete, Tevita Kuridrani, Billy Meakes, Izaia Perese, Nick Phipps, Joe Powell, Curtis Rona, Henry Speight.
