Jordan Petaia eyeing fullback switch but Wallabies start likely to come on wing

Are the Wallabies finally building some depth? (2:42)

Sam Bruce and Christy Doran discuss Dave Rennie's considered expansion of the Wallabies squad and how it has led to an increase in depth. (2:42)

While he's been earmarked as a long-term fullback option at Test level, Jordan Petaia is set to take advantage of the absence of star Wallabies winger Marika Koroibete.

Workhorse Koroibete will miss the final round of the Rugby Championship on the Gold Coast on Saturday, as the Wallabies aim to secure their fourth successive win with another victory over Argentina.

Australia earned a 27-8 defeat over plucky Argentina in Townsville last Saturday, which came after two wins over world champions South Africa.

Koroibete has already flown home to Melbourne to spend time with his young family, which includes a newborn, before Australia's squad departs in late October for its UK tour.

Petaia replaced Koroibete as starting winger in the opening Bledisloe Cup Test after the latter was among a trio of Rebels players ruled out for off-field disciplinary reasons.

But the Queenslander has had limited game time off the bench since.

The 21-year-old said he felt he'd learnt plenty watching Koroibete and fellow Test winger Andrew Kellaway in action.

"Marika's work-rate across the park, it's probably second to none," Petaia said on Tuesday.

"Not many players get across (the field) like him so it's been huge for me watching him work hard, which has been good thinking about my own game."

While happy for any additional game time, Petaia said he wanted to move into the fullback jersey long-term.

There's an outside chance Wallabies coach Dave Rennie could start him there against the Pumas, but Reece Hodge is the more likely option after a solid outing in Townsville last week.

"Eventually I'd like to take on at 15 role, whether that happens at the Reds or later this year, I don't know what that looks like," Petaia said.

"Obviously the more positions we can cover the better for the team and it's good for my growth as well."

Petaia's season stalled after a quad injury ruled him out of Super Rugby Trans-Tasman competition and also the France Test series in July.

He has also suffered a serious foot injury and had a shoulder reconstruction during his young career but Petaia said he was now fighting fit.

"My body is feeling the best it's felt in years," Petaia said.

"I will just keep working hard and making sure that the strength and conditioning team is conditioning me well so I will stick with that program and not get complacent.

"It definitely feels good not to have to worry about all those previous injuries."