Wallabies captain Stirling Mortlock insists Australia is definitely heading in the right direction despite a shaky start to their Tri Nations rugby campaign.

Losses in their first two Tri-Nations games have left Australia languishing last on the ladder with just one bonus point.

Now in their second season under New Zealand-born coach Robbie Deans, Australia is still in a "growth pattern", according to Mortlock.

"It may be quite frustrating at the moment because the results haven't showed the work that we've done," Mortlock told reporters at Sydney airport on Monday after the team returned from South Africa.

"I've got full confidence and I'm pretty sure the whole group does that we're still heading in the right direction and it will only be a matter of time before the results also show that."

Both Mortlock and Deans praised the defensive effort of the Wallabies in Cape Town, where they conceded only three points during a period where they were down to 13 men for almost 10 minutes.

"Probably a year, or a year and a half ago, we would have got absolutely slaughtered in those conditions, but the boys dug in deep, that's a real positive," Mortlock said.

"We've just got to assess our discipline and our ability to take advantage of opportunities."

Deans also extracted positives from the loss, believing Australia out-performed the Springboks in all areas apart from discipline and the lineouts.

Mortlock expects to miss Australia's next Tri Nations fixture against New Zealand in Sydney on Saturday week because of a knee injury.

Although X-rays in South Africa cleared him of a break, Deans fears cartilage damage could rule his skipper out for their four remaining Tri-Nations matches.

Deans said he would disclose the identity of the replacement captain for the August 22 game when the team was announced.

Flanker George Smith, who has captained Australia before, is among the leading candidates for the job.

Brought to you by AAP © 2024 AAP