Rachel McLachlan and teenager Emma Orr return from injury to start for Scotland in the must-win Pool A game with Australia on Saturday.

Megan Gaffney and Louise McMillan are the players to drop out, while Hannah Smith switches to the wing.

Eva Donaldson has been called into the squad to replace Eilidh Sinclair.

Back-row Sinclair's tournament is over because of the elbow injury she suffered against Wales.

Australia, 10th in the world rankings and three places higher than Scotland, began with a 41-17 loss to hosts New Zealand, but are big favourites against Bryan Easson's side.

Scotland head coach Easson said: "We haven't faced Australia before so it's going to be a different contest to last weekend.

"With a six-day turnaround, we've had a greater focus on analysis than usual and it's been important that the players recover and reset ahead of this Saturday.

"It's great to have Rachel McLachlan and Emma Orr available for selection again. Australia have an abrasive back-row and we know that Rachel brings physicality to her game, while Emma really impressed us throughout the Women's Six Nations after making her debut earlier this year.

"It was excellent to see some travelling support here in Whangarei last weekend and I know that the support from back home has also been outstanding."

Scotland: Chloe Rollie; Rhona Lloyd, Emma Orr, Lisa Thomson, Hannah Smith, Helen Nelson, Caity Mattinson; Molly Wright, Lana Skeldon, Christine Belisle, Emma Wassell, Sarah Bonar, Rachel Malcolm (capt), Rachel McLachlan, Jade Konkel.

Replacements: Jodie Rettie, Leah Bartlett, Elliann Clarke, Lyndsay O'Donnell, Mairi McDonald, Sarah Law, Evie Wills, Shona Campbell.