Baxter starts as Reilly hails 'formidable' Irish line-up
It says a lot about the strength in depth of the Ireland squad that Tom Tierney can leave a former World Player of the Year nominee on the bench.
Sophie Spence has had problems with concussion last season but her timely return during the Six Nations was seen a major boost to Ireland's chances of winning a home World Cup.
But the powerful second-row has to make do with an impact role for now at least as Tierney shuffles his pack and brings Ashleigh Baxter, a former winger, into the back-row, while regular No 8 Paula Fitzpatrick switches to the engine room in place of Spence.
In recent years, Spence and Marie-Louise Reilly's second-row partnership was one of the bedrocks on which Ireland's game-plan was based but this is a new-look pack.
"I think it just shows the progression of our team in the last couple of years that we have got strength in depth now - everyone is fighting for their place," Reilly maintained. "Baxter can come in, she's a formidable rucker so flanker is going to suit her down to the ground.
Talented "And then Paula Fitz is just so talented. She can really can play in any position. She would have played 10 for her club before so she's more than capable of playing that role. We've got a huge bench coming in then so it's going to be a formidable team."
Ireland's set-piece is generally very strong and against an Australian outfit who are largely made up of sevens specialists looking to thrive in broken play. Reilly knows that her side's scrum and lineout are crucial to getting off to a winning start.
"As ever, a game can really swing with your set-piece," the Leinster lock added. "We pride ourselves on our scrum and lineout ability. We will look to try and gain an advantage there.
"They have a lot of talent with the Sevens players coming in. We too have Sevens players coming in. I think we are on an even keel in that regard.
"For us, it is just another team. We do our analysis to find their strengths and weaknesses and plan our game around that."