Japan's thrilling 34-32 win against South Africa has put the Wallabies on notice as they prepare to start their campaign against Fiji on Wednesday (Thursday 1.45am AEST).

It's a timely reminder for the 'pool of death', and the reason why Wallabies lock Will Skelton copped a spray from coach Michael Cheika when he dropped a ball at training this week.

Most expect the Wallabies to fight with England and Wales to advance to the next stage of the tournament.

But after Fiji pushed England to the limit in the World Cup opener before succumbing to pressure, the Wallabies are treading cautiously ahead of the clash in Cardiff.

That's why Cheika is on edge to ensure no stone is unturned and the Wallabies don't get lured into a loose game plan of offloads and poor discipline.

"I think they were going to come hard no matter what and we're going to try to showcase our type of footy, whatever the occasion," Skelton said.

"If we played Uruguay in the first game, it would be the same. We wouldn't take anything for granted.

"We'd play a smart game with power and physicality. I'm just really looking forward to it, they're going to be up for it now.

"They got 80,000 at the game [against England]. They're going to be battle-hardened and ready for a big contest against us."

Wallabies coach Michael Cheika is finalising his selections with Skelton fighting for a spot in the second row.

But the giant NSW Waratahs star said he was happy to play a cameo from the bench and vowed to leave a path of destruction when he's on the field.

"Whenever I start on the bench, I have a specific role to be a finisher [and] to bring impact," Skelton said.

"I always try looking for those advantages when guys are tired, looking at their weaknesses and trying to provide a platform."

The Wallabies have been forced to bide their time at their Bath sanctuary while they watch other teams begin their World Cup tournaments.

Most senior players haven't been involved in a game since the last Bledisloe Cup match in August and the players are itching to get on to the field.

Watching Japan score in the 84th minute to clinch their first World Cup win since 1991 will add extra motivation as less-fancied nations attempt to claim big scalps.

It means that taking on a fired up Fiji will be a danger game before backing up against Uruguay four days later.

Skelton also said the Wallabies were prepared to adjust their tempo with referee decisions and the television match official chewing up playing time in some of the opening contests.

The first half in the England-Fiji match went for 54 minutes as referee Jaco Peyper constantly sent decisions to the video replay.

The Wallabies want to play a fast-paced game, but their plans may fall apart if opposition teams or delayed refereeing decisions stifle their tempo.

"The ref is going to have their say, but we're going to try and play our style of game against whatever opposition comes forward," Skelton said.

"You've got to take every moment when it comes. You can't give the ref 50-50s, you can't give the opposition 50-50s.

"An example from training today – I threw an offload which went to ground. I got sprayed by the coach, but that's something I should have held on to.

"Those little things will give the ref the opportunity to make it a stop-start game."

Fiji's biggest threat is powerhouse winger Nemani Nadolo, who is shouldering his country's hopes of World Cup success.