The rivals clash in Oita on Saturday in a rematch of the 1995 and 2007 quarter-finals and England are strong favourites to complete a seventh successive victory over the Wallabies under Eddie Jones.
Their last defeat in the fixture was far more significant than each of those wins, however, as a 33-13 rout at Twickenham consigned them to a harrowing group exit in the global showpiece four years ago. Australia are dangerous World Cup opponents, even allowing for their decline since reaching the final in 2015, but Youngs insists England have yet to reveal the extent of their armoury in Japan.
“Australia are very clever in how they attack and I have always found them challenging in that aspect,” Youngs said.
“That game in 2015 was one where they came up with a play we had never seen before – Bernard Foley comes around and plays it back inside to Kurtley Beale.
“You think they are going to do one thing and they do something completely different.
“It’s important we prepare for that. I like the way they play with their attacking mindset – and off the back of that you always get chances.
“We haven’t shown a huge amount in any of our games. Against America and Tonga we kept it pretty low-key. Against Argentina we had a bit more in the playbook but again didn’t need to show our hand.
“We will make sure we are right and ready to go and have things we haven’t had to use yet.
“You know that there are certain areas of the game you are strong against Australia. That record gives you belief but we won’t read too much into it.”
Youngs is only one of four players in Jones’s squad, alongside Courtney Lawes, Manu Tuilagi and Dan Cole, to have played in a World Cup quarter-final – the 19-12 defeat by France in 2011.
Of the quartet just Youngs and Tuilagi are likely to start at Oita Stadium, leaving England to face Australia with precious little experience of knockout rugby on the global stage.
“I was thinking the other day about when we played France in the 2011 quarter-finals,” said Youngs. “At that stage they were deemed to be in turmoil.
“My experience is that you can’t read into what happens in the past, it’s just about that 80 minutes. Don’t believe your own hype as a side.”
Add in England’s enforced two-week break due to the Pool C decider against France being cancelled because of Super Typhoon Hagibis, impacting on their momentum, and the Wallabies have cause to feel emboldened.
After four years of build-up to Japan, Youngs admits the prospect of it being over on Saturday is unthinkable but denies their lack of high-quality opposition en route to the last eight is a hazard.
“I certainly don’t feel like we’re undercooked. I think we’re in exactly the right spot. We haven’t had to show a huge amount yet –and that’s a good thing.”