Wallaroos admit major shortfall ahead of Black Ferns rematch

The Wallaroos will benefit from a gruelling block of high-intensity fitness work when they look to create history against the Black Ferns.

Australia's national women's rugby union side are looking to break through for their first ever win over New Zealand when they take the field in Christchurch on Saturday night.

The ledger reads an unfortunate 20-0 in New Zealand's favour, but captain Shannon Parry says they're drawing strength from their last hit-out.

Two months ago, in the driving rain at Tauranga for the Pacific Four series, Australia led 10-5 at half-time before succumbing 23-10.

"Against the Kiwis, we were in it until the 50th minute," Parry told AAP, putting the fade-out down to fitness.

"But the engine, the battery was getting a little bit empty.

"The fitness base wasn't where we needed it to be. So we've worked really hard on that in the eight weeks since that competition."

Since then, the Wallaroos have submitted themselves to the gruelling yo-yo test, which Parry says "some players have nightmares about when they hear it's coming up".

"But that was the point of the Pacific Four series," she said.

"It's been really good to see the improvements across the whole group ... we're definitely in a lot better shape now than where we were eight, 10 weeks ago."

On top of the improved fitness, Australia will also boast two new faces in Christchurch.

Bree-Anna Cheatham has recovered from hip surgery earlier this year and will run out in a gold shirt for the first time after winning selection as loosehead prop.

Super W Brumbies No.8 Grace Kemp, who Parry called a "young whippersnapper" will also make a starting debut.

Australia, the world No.8s, placed last in the Pacific Four series, lost a tight contest with the USA 16-14 in Auckland before finishing with a 22-10 loss to Canada in Whangarei.

That tournament, and the fortnight's upcoming hit-outs against the Black Ferns in Christchurch and Adelaide for the O'Reilly Cup, form the Wallaroos lead-up work for October's World Cup.

"As a collective, to see where we are out again some of the world's best teams, it's so pleasing for our preparation," Parry said.

- Ben McKay