Image source, BBC Sport

Captain Katie McCabe says the Republic of Ireland "are not just happy to be here" and will push Australia in their World Cup opener.

"We don't just want to create history. We want to leave a legacy back home," said McCabe.

Arsenal's McCabe said the Republic are proud to carry the underdog tag and the pressure is all on Australia, who will be favourites in front of an 82,000-strong crowd.

"We know we are making our debut but we know what we want to do," she said.

"We want to give Australia, Canada and Nigeria the hardest games possible. It's going to be exciting.

"We know what Australia have. They have quality all over the park, but we know what we can do all over the pitch. We are fully concentrated on tomorrow."

Karen Bardsley
Former England and Manchester City goalkeeper on BBC Radio 5 Live

Image source, Getty Images

Ireland will be bolstered by the fact that Sam Kerr isn't playing tonight, but Australia are not a one woman team.

Their side is stacked. Well balanced, plenty of experience, and lots of youthful enthusiasm.

They are in great form heading into this game tonight as well.

Andy Gray
BBC Sport NI at Stadium Australia

Around 4,000 fans are expected to have made the trip across the world for the World Cup, and many Irish expats in Australia are also set to descend on Sydney.

Australia may have home advantage but the Irish support, although smaller in number, will definitely make themselves heard and it should be a special atmosphere.

The family of Irish defender Megan Connolly are some of those who have made the trip.

“She’s chilled, there’s no fazing her,” said sister Nicole.

“I think we’ll do pretty well,” added mum Freda. “The Australians think they are going to win but I’m not sure. We have to believe.”

Brother Luke said they were going to go to the stadium five hours early to drink the occasion in.

“I think they are underestimating the amount of Irish who are going to be there.”

Dad Michael added he thinks Ireland will score from a set piece and will hold out for the win.

“It’s just a co-incidence that Megan takes corners,” joked Luke.

Image source, Inpho

As the Republic of Ireland prepare to get their first-ever Women's World Cup campaign underway, here's an in-depth look at Vera Pauw's 23-player squad.

There's a mix of experienced heads, household names and players for the future, giving a nice balance to the selection.

But can Pauw get the right balance for the perfect start against co-hosts Australia?

Image source, Getty Images

Key Republic of Ireland midfielder Denise O'Sullivan has been passed fit and is in the starting line-up after being taken to hospital following Friday's abandoned friendly with Colombia.

Scans revealed she suffered a badly bruised shin, but manager Vera Pauw said she is "fine and will play" against Australia.

Much was made of the decision to end the Colombia game after only 20 minutes following "overly physical" tackles on Republic players, but captain Katie McCabe said "full focus" is on Australia.

"We knew Colombia were going to be physical - it is the case in every game," she said.

"We don't shy away from that and it is ingrained in us. We are prepared for Australia to be physical.

"We have looked at the games they have played and they don't shy away from that either. We are prepared to match it."

Emma Smith
BBC Sport reporter at Stadium Australia, Sydney

There were audible gasps around the press room at Stadium Australia as the news spread of Sam Kerr's injury.

It wasn't supposed to go like this - the captain, the record scorer, the tournament poster girl, to be ruled out of the showpiece opening match.

Australia have a very talented squad, particularly in attack, so may be able to replace her goals. Replacing Kerr's leadership and aura may be a different matter.

Image source, BBC Sport

With Australia v Republic of Ireland coming up shortly, let's have a better look at Group B.

The two teams in action today are joined by Canada and Nigeria, who play at 03:30 BST on Friday.

Australia

World ranking: 10

Manager: Tony Gustavsson

World Cup 2019: Last 16

Canada

World ranking: 7

Manager: Bev Priestman

World Cup 2019: Last 16

Republic of Ireland

World ranking: 22

Manager: Vera Pauw

World Cup 2019: Did not qualify

Nigeria

World ranking: 40

Manager: Randy Waldrum

World Cup 2019: Last 16

You can read more about Group B here.

BBC Radio 5 Live

Image source, BBC Sport

Listen to the build-up and live commentary of the Republic of Ireland's first ever Women's World Cup match as they take on co-hosts Australia in Sydney at 11:00 BST.

You can listen using the audio icon at the top of this page or click here to listen on BBC Sounds.

I wonder if Rachel Brown-Finnis would have had the same prediction if she had known Sam Kerr would be absent for Australia.

Image source, BBC Sport

Australia are going to be a real force at this World Cup and it is going to be so exciting for them to be co-hosts.

We know how amazing it was for England to host the European Championship last year and this is Australia's chance to show what they can do, on a global stage.

This is a really difficult start for Republic of Ireland and I think Vera Pauw will set them up to be difficult to beat.

They have got a few attacking weapons too, especially from set-pieces, but I still think Australia will begin with a win.

Brown-Finnis's prediction: 2-1

BBC Sport football expert Rachel Brown-Finnis is predicting the outcome of all 64 games at the 2023 Fifa Women's World Cup.

She has started with the opening games in each group, which you can read here.

Emma Sanders
BBC Sport in Sydney, Australia

Image source, BBC Sport

Plenty of Irish supporters here in the fan park in Sydney’s busy Darling Harbour area.

I told the four people pictured above about Sam Kerr’s injury absence and the man immediately joked: “Well, now we’ve won then!”

It’s certainly welcome news for these fans. One of them said: “It’s still going to be tough. But we have a chance.”

The couple below are on holiday here but always planned to come to the fan festival to watch the game and they’ve managed to find some shirts from a relative who lives here.

Image source, BBC Sport

Ellen White
Former England striker on BBC One

Image source, Getty Images

This is huge.

Sam Kerr is the prolific scorer that Australia rely on. The whole world is watching and for her to potentially miss two games is sad for them.

But someone can step up. It gives someone the opportunity to step up, grab it with both hands and be the next star.

Image source, Getty Images

Sam Kerr and Australia must be gutted.

The Matildas captain was supposed to lead her country onto the pitch for their first match at a home World Cup.

Read more on how Kerr developed into one of the world's best strikers and an Australian icon.

Well, there's only one place to start. Australia captain Sam Kerr will miss tonight's opener - and their second game with Nigeria - after picking up a calf issue in training.

As the poster girl for the tournament and the Matildas' superstar, it is heartbreaking for Kerr to be ruled out on the eve of her home tournament.

Steph Catley will captain the side, and Mary Fowler and Caitlin Foord will lead the line.

It's an expected line-up for Vera Pauw in the Republic of Ireland's first World Cup match.

Denise O'Sullivan is fit to start after recovering from a shin injury, and the Irish will be captained by Arsenal's Katie McCabe.

With five defenders, it is an approach based on containment and that is unlikely to change even with the news about Kerr.

Image source, BBC Sport

In front of an expectant home crowd, all eyes were supposed to be on Australia star striker and captain Sam Kerr today.

The Chelsea forward scored 12 goals and provided five assists as the Blues won a fourth Women's Super League title in a row last season.

Kerr will not be playing at Stadium Australia, and it's a good thing for the Republic of Ireland that manager Vera Pauw said her team cannot focus on one player.

"We have our game plan. Part of that is dealing with Sam but also the rest of their players," Pauw said.

"Australia is not just Sam Kerr. We have analysed them and set out our game plan."

Australia captain Sam Kerr is out of tonight's game against the Republic of Ireland with a calf injury.

Kerr will also be absent for the co-hosts’ second group game against Nigeria on Thursday, 27 July.

You can follow this breaking story as it develops here.

Image source, Getty Images

Before we get started with our build-up, we've got some breaking news to bring you from the Australia camp.

The wait is over. Welcome to day one of the 2023 Women's World Cup.

A month of first-class football action awaits in Australia and New Zealand and in 31 days time, 32 teams will have been whittled down to just two.

A third World Cup in a row for the USA? Can the Lionesses relive their Euros glory? Or is it time for an underdog to lift the trophy?

Image source, Getty Images

We've had one game kick off in New Zealand already to get the World Cup started, now it's Australia's turn.

We're turning our attention to Sydney's Stadium Australia, where 82,000 fans are expected to turn out for the Matilda's first fixture against the Republic of Ireland at 11:00 BST.

For Australia, it's their eighth consecutive World Cup, while the Republic of Ireland are appearing at their first ever women's major tournament.