The other change is Tomas Cubelli starting at scrum-half ahead of Gonzalo Bertranou, who drops out of the match-day 23.

"I think I've made the right choices," said Cheika, who led Australia to two quarter-finals in 2015 and 2019, going on to make the final in his first experience.

"I've known Wales for a long time, even when I was Australia coach. I know their strong points: defence, their kicking game and attack if they're ready to attack, their players are very fast and tough for defenders."

Argentina qualified for the last eight as runners-up behind pool winners England, but Cheika insisted those group games were now behind his squad.

"Whether we've won or lost games is not important, what's important is the next game," he said.

"For us, what is important is how we will attack and our fundamentals, our basics. Our defence is going well, it's our attack that needs to step up for this game.

"We need continuity in attack and I believe our kicking game will be very important. The Welsh use the boot much more than we do and and it will be up to us on how we best use our kicking game."

Julian Montoya skippers the side from hooker, flanked by Thoms Gallo and Francisco Gomez Kodela, while Guido Petti and Tomas Lavanini pack down in the second row.

Juan Martin Gonzalez and Marcos Kremer combine with Isa in the backrow, while Cubelli has Santiago Carreras at fly-half.

'Consistency a goal'

Santiago Chocobares and Lucio Cinto pair up in midfield in front of a back three comprising full-back Juan Cruz Mallia and the wing pair of goal-kicking Emiliano Boffelli and Mateo Carreras, a hat-trick hero against Japan last weekend.

"Consistency is a goal, that's clear," Cheika added. "How to deal with errors, pressure and where each player can find the resources to deal with their individual challenges.

"We need our goal to be clear and it's the same goal for every match: to win it. If we're consistent we're on the right road."

Cheika said he was happy to be "part of the top eight, in the quarter-finals", crediting almost two years of hard work together.

"That will give us that feeling of being ready for a game where we know Wales are favourites," the Australian said.

"We know we're going to have do something different, something special around the game on Saturday so we can be competitive with the Welsh."

Cheika added that being tagged favourites or underdogs actually changed nothing for the team.

"Whether we're favourites or not, that's for the press and supporters, we're not bothered by that talk," he said.

"What matters for us is the 80 minutes between the referee starting and finishing the game."

Argentina (15-1)

Juan Cruz Mallia; Emiliano Boffelli, Lucio Cinti, Santiago Chocobares, Mateo Carreras; Santiago Carreras, Tomas Cubelli; Facundo Isa, Marcos Kremer, Juan Martin Gonzalez; Tomas Lavanini, Guido Petti; Francisco Gomez Kodela, Julian Montoya (capt), Thomas Gallo

Replacements: Agustin Creevy, Joel Sclavi, Eduardo Bello, Matias Alemanno, Rodrigo Bruni, Lautaro Bazan Velez, Nicolas Sanchez, Matias Moroni