Both sides are chasing their first win but only the Wallabies could feel particularly aggrieved at their precarious situation, having strode confidently into the tournament under new coach Ewen McKenzie.
After three rounds, the Wallabies sit bottom of the table behind the underdog Pumas and their coach's pledge to win by playing "the Australian way" have been made to look foolish by two losses to New Zealand and a record hiding by South Africa on home soil.
With alarm bells ringing Down Under and rugby writers moaning of fans turning away from the game, McKenzie has not gone back to the drawing board so much as to rip it off the wall and hurl it out of the window.
Out-of-sorts scrumhalf Will Genia, the Wallabies' "only world XV player" in the words of local pundit Greg Growden, has been dropped to the bench and Ben Mowen, a backrower with only six tests under his belt, has been awarded the captaincy.
The stunning gambit has been branded Australian rugby's 'line in the sand' moment, a move to shock an underperforming side out of its torpor and head off a potentially cataclysmic defeat against highly physical opponents desperate to post their first win in the tournament.
McKenzie, who raised eyebrows by suggesting he would need to "dumb down" the game plan after the painful 38-12 loss to the Springboks in Brisbane, shrugged it all off as tinkering.
"There are little areas of the game where we can tweak things. We've made some minor adjustments," he said this week.
"If you change big things, you actually don't know what makes the biggest influence.
"So with small changes - which is what we've been doing for the last few weeks - we'll get there."
Beset by a shocking run of injuries, Australia under former coach Robbie Deans hung tight to defeat Argentina twice last year and finished a creditable second behind the champion All Blacks.
No matter the gap in class between the sides, a repeat of last week's effort against South Africa would almost certainly see the Wallabies crumble to defeat against the Pumas, who will look to exploit the hosts' brittle pack in the scrum.
After being humiliated 73-13 by the Springboks in Soweto, Argentina regained their pride with a narrow loss in the return match at Mendoza and surprised the All Blacks last week in Hamilton with an early try before being reeled in.
Head coach Santiago Phelan has shaken up his backline, recalling scrumhalf Tomas Cubelli and centres Felipe Contepomi and Gonzalo Tiesi among four changes in the hope of bringing more firepower to Subiaco Oval.
But the forwards, who were combative against New Zealand's formidable pack, are untouched barring a promotion to the starting side for hooker Agustin Creevy.
Led by captain Juan Martin Fernandez Lobbe, Argentina have also had some insights in how to beat the Wallabies from former World Cup-winning coach Graham Henry, whose New Zealand teams dominated Australia for the better part of a decade.
"He added a lot of confidence and knowledge in the way to attack," Contepomi said of Henry, who has worked with Argentina as a coaching consultant.
"He knows the Wallabies much better than we do, and it's great to have his inside knowledge... He can add to our rugby culture."
Australia team: 15-Israel Folau, 14-James O'Connor, 13-Adam Ashley-Cooper, 12-Christian Leali'ifano, 11-Nick Cummins, 10-Quade Cooper, 9-Nic White, 8-Ben Mowen (captain), 7-Michael Hooper, 6-Scott Fardy, 5-Kane Douglas, 4-Rob Simmons, 3-Ben Alexander, 2-Stephen Moore, 1-James Slipper
Replacements: 16-Saia Fainga'a, 17-Scott Sio, 18-Sekope Kepu, 19-Sitaleki Timani, 20-Ben McCalman, 21-Will Genia, 22-Matt Toomua, 23-Tevita Kuridrani
Argentina: 15-Juan Martin Hernandez, 14-Horacio Agulla, 13-Gonzalo Tiesi, 12-Felipe Contepomi, 11-Juan Imhoff, 10-Nicolas Sanchez, 9-Tomas Cubelli; 8-Juan Manuel Leguizamon, 7-Pablo Matera, 6-Juan Martin Fernandez Lobbe (captain), 5-Julio Farias Cabello, 4-Manuel Carizza, 3-Juan Figallo, 2-Agustin Creevy, 1-Marcos Ayerza
Replacements: 16-Eusebio Guinazu, 17-Nahuel Lobo, 18-Juan Pablo Orlandi, 19-Mariano Galarza, 20-Benjamin Macome, 21-Martín Landajo, 22-Santiago Fernandez, 23-Lucas Gonzalez Amorosino
Referee: George Clancy
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