The 48-17 humbling to Michael Cheika’s Pumas in San Juan meant Australia dropped to seventh in the latest world rankings, slipping behind sixth-placed Scotland.
That equals the worst-ever ranking for the Wallabies which they also held in 2018 following a loss to Argentina.
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Ireland remain atop the rankings after their historic series win in New Zealand, with France second and South Africa third.
The All Blacks leapfrogged England into fourth with their stirring 35-23 upset of the world champion Springboks in the Rugby Championship on Sunday.
The Wallabies sit second in the tournament after two rounds but Sunday’s result was a major blow to their title chances given the Pumas are perennial wooden spooners.
“I’ve got full confidence in Dave as the right man to lead us to the World Cup,” Marinos told the Sydney Morning Herald.
“There are tweaks and things they know they need to address, and I’m really confident they’ll (do) that on and off the field – and I’m confident that we’ll get there and be successful.”
A horrific injury toll has hurt the Wallabies, who are also without inspirational captain Michael Hooper as he takes a break to prioritise his mental wellbeing.
There has been no indication that Hooper will return for the next assignment: a daunting clash with the smarting Springboks at the Adelaide Oval on August 27.
“I’m not looking for excuses. This team prepared well,” said Rennie, who is contracted until the 2023 Rugby World Cup in France.
“We lacked a bit of cohesion. If we’re a bit more clinical, we hadn’t given sloppy tries, especially early, then she’s a different game.
“We’ve got to be better, we’ve got to own that. It’s on us as coaches. It’s on the players.
“If it’s on to offload we want to offload but there are a number of times where (taking) a ruck’s not a disaster.
“We just need to get one more ruck and be patient and build pressure.
“We released the pressure valve a number of times by maybe throwing a pass that wasn’t on. We’re better than that.
“But you can talk about all you like – you’ve got to put it on the park. And what we know is you can’t give soft points up and you’ve got to take opportunities.
“Couldn’t buy a trick tonight.”
NEW PODCAST! Wallabies prop Scott Sio joins Sean Maloney and Andrew Mehrtens to try and make sense of a dramatic round two of the Rugby Championship
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