McKenzie defended the performance of under-fire five-eighth Kurtley Beale and ruled out mass changes to the side that drew one Test with the All Blacks and fell to their third-worst loss against them a week later.

But the coach conceded the side was under the pump and needed to front up physically in Perth on Saturday week.

"While tactically the games are different, you'd like to think most of the time you're picking the best player you've got in a position," McKenzie told panel show Rugby HQ.

"In terms of mass changes, I don't see that happening but strategic changes are quite possible."

What that means for Beale and teammate Bernard Foley – who have both started Tests at No.10 this year – is unclear.

When asked whether Beale's return to the No.10 Test jersey had worked, he replied: "People are going to always judge those things after the fact."

"We had a plan back in June about who we thought were the two best options for us. Foley played there and did all right in the French series and we had ideas to use Beale there as well, but he played in other positions due to injuries and things that happened during the games, so we didn't get the chance to look at that.

"We were very confident about [using Beale at No.10], I've known Beale for a long time at No.10 and while he hasn't played there of late he's played a lot of rugby there. He stepped up in different ways. It's a tough environment to play the All Blacks, it's not an easy day at the office.

"I was really pleased [with] his goal-kicking, that was an area people really questioned, he missed one kick out of nine. Things like that were really positive for us. But we'll look at all that. He brings different things to Bernard, and that's why we picked him."

Foley's more traditional carriage in the No.10 role and his appetite for the physical contest might suit the Wallabies' plans to upset the direct and physical Springboks, while Beale's gifted playmaking could once again provide the spark to help Australia exploit any fatigue in South Africa's ranks in the second half.

Either way, the Wallabies will be busting to prove they are not the side that was bashed and bullied by the All Blacks at Eden Park.

"We're under pressure. We had a period there when we were winning each time we played, but those things only last for so long," McKenzie said.

"We were able to stop the All Blacks the week before from their winning run and they stopped us as well.

"The trick is to rebound. It doesn't get much easier when we play the Springboks ... but it's still about being physical and fronting up."

The Wallabies coach also revealed the shock of last week's loss was taking a while to shake off.

"There will be no more disappointed person than myself," he said. "It's been a tough couple of days, I don't suffer losses well at all, it's been a hard one to put aside.

"But I can go back a week before that and we should have won the game [a draw, in Sydney]. I know how the game works, you can get on the wrong side of the scoreboard pretty quickly these days, we put 50 on France in the first Test and it was 6-3 in the second Test.

"Things change pretty quickly in a week. We just need to have the right attitude, and dust ourselves off and say that wasn't our best work."

There are just three Tests left in Australia this year – South Africa in Perth next weekend, Argentina on the Gold Coast and the third Bledisloe in Brisbane in October.

McKenzie acknowledged the disappointment of losing another chance to win back the Bledisloe Cup, but hoped the side would be judged over the longer term.

"It's disappointing because we put a lot of work into the preparation and we also created a lot of expectation," he said. "When you don't meet expectations that's disappointing.

"But the last 12 months have been pretty positive so we just need to keep at it. You don't want one performance to define you good or bad. Consistency over time is important for Australian rugby and we've been doing that.

"We need to get back at it and keep going and hopefully performance over time will be the most important thing that people judge us on."