Wales head coach Warren Gatland has hinted at possible changes to his line-up that will face Australia amid concerns over his "battered players".
The loser of Saturday's Twickenham clash is likely to take on South Africa in the quarter-final, with the winner set to face either Scotland or Japan.
And it will be interesting viewing when Gatland names his team as after a heavy workload in the Pool of Death, it might be worth resting his stars.
"We just have to assess how battered these players are and where there bodies are," Gatland told Press Association Sport.
"We need to decide whether we put them in next weekend or keep them for the following week.
"We will look and see what happens over the next couple of days in terms of selection.
"We do have other options, and depending on what style of game we want to play and what sort of game-plan we want will influence us in terms of the few changes we do make.
"Potentially, whoever we do play in the quarter-finals — whether it's South Africa, Scotland or Japan — we have had some success.
"We lost in the last Test in Japan in 2013 when I was on Lions duty. But we have had pretty good success in the last eight years against Scotland, and winning that game against South Africa last autumn was a huge milestone for us."
Meanwhile, openside flanker Justin Tipuric has praised the quality of Australia's back-row trio ahead of the game and believes Scott Fardy deserves more credit.
"It's a pretty special back row," Tipuric said. "Their number six (Fardy) doesn't get enough credit. He does a lot of the donkey work.
"Whoever plays there (back row) for them, they have strength in depth no matter what.
"The breakdown is a strength for them, and we need to make sure we look after that ball. You are up against the best with Australia, and it's going to be a good test."