Argentina fly-half Juan Martin Hernandez has admitted his side were surprised to see Will Genia left out of Australia's starting line-up for Saturday's match in Perth.
"It is a surprise. He is one of the best in his position in the world. Maybe it is a tactical thing," Hernandez said.
"Maybe they will put Genia into the game with 30 minutes to play to give another rhythm to the Test when perhaps we are more tired. Maybe it will be a good tactic you never know."
Brumbies half-back Nic White will take over, in his first start for the Wallabies, while Ben Mowen will skipper the side in just his seventh Test.
Genia's demotion has been regarded as McKenzie getting tough on his team - who have lost four Tests in a row stretching back to the decisive defeat to the British and Irish Lions in June.
Australia are also without a point after their winless start under their new boss in the Rugby Championship and defeat in Perth would set a new record for consecutive losses in a home season.
"It definitely hurts," utility back James O'Connor, who hinted he could sign for former club Western Force as early as next week, said.
"I leave everything out on the field. I play my guts out.
"It is frustrating because I can see we are not far off and the scoreboard has blown out.
"We are making a lot more tackles than people expect but when teams are making breaks we are not covering well.
"We could do with a few more meat pies (tries)."
Australia were beaten 38-12 by South Africa in Brisbane last weekend, following heavy losses to New Zealand (twice) and the Lions.
Despite that Hernandez remains wary of a Wallabies side that he believes is showing signs of piecing together the attacking style of rugby McKenzie desires.
"All the sides the Wallabies have played recently have been very good," the 31-year-old said.
"Always, results talk more but the press has been tough on the Australian team.
"They are a very big challenge for us.
"I love the Wallabies game. They are one of the best in their attacking structures that I know.
"The opposition has been defending them well but when I watch the Wallabies I see what the backline have been practising. If they finish all the moves they do have they are very dangerous."
Argentina are still looking for their first Rugby Championship win since entering the competition last year.
They led the Wallabies 19-6 on the Gold coast 12 months ago only to allow the home side to rally, but Hernandez said any desire to grab a breakthrough win would not play on their minds.
"Victory comes as a consequence of playing good rugby and that is what we have to concentrate on," he said.
"We are learning from the games we have played and getting more experience to hopefully control games better with our rhythm as a team."