Israel Folau could miss Australia's Pool A decider against Wales at Twickenham on Saturday night through injury.

While Warren Gatland's side have been hit hard by injuries both before and during the World Cup, the Wallabies also have their concerns following last weekend's physical encounter against England with Rob Horne also in serious doubt.

Horne left the field during the 33-13 victory carrying his shoulder while Folau rolled his ankle and was later spied in a moon boot.

Israel Folau is hauled down by Owen Farrell© David Rogers/Getty Images

"Rob's in doubt for this week, most likely not going to play," Larkham said. "The other injury concern at the moment that we've got is Izzy.

"He came off the field in the game with a bit of a sore ankle and didn't train yesterday [Monday] so we're going to see how we pulls up today -- we're not even sure whether he's going to train.

"So to turn it around and look at our squad, they're pretty significant [omissions] and you put Michael Hooper [who has received a one-week ban] into that case as well. They're fairly significant."

Utility back Kurtley Beale replaced Horne against England while Drew Mitchell looms as a likely starter on Saturday due to his experience on the left wing.

Beale would be the natural selection option should Folau fail to recover in time, given his experience at full-back at Test level.

Meanwhile, assistant coach Stephen Larkham says Australia's recent domination of Wales holds "no relevance" for Saturday's meeting.

The two sides will battle for top spot in Pool A and a quarterfinal with either Scotland or Japan -- providing South Africa make light work of the United States, as expected -- with the Welsh needing to snap a run of 10 straight defeats dating back to 2008.

But the setting of a World Cup and the change in leadership within the Australian camp means the Wallabies will take little from their lengthy winning run, according to Larkham.

"In terms of previous games, this is my first time [as a coach] against Wales in the Australian outfit and for a number of guys it's their first game [against Wales] in this squad as well," Larkham said.

"You know Michael [Cheika] took over at the end of last year, and tried to change a few things within the culture and within the playing style and I think that's starting to come to fruition now. And looking back at those old games against Wales, it has no relevance this weekend."