The Queanbeyan defender replaces Alleway in Ante Milicic's Matildas squad for the 2019 FIFA Women's World Cup after Alleway couldn't recover from her foot injury suffered during the team's preparatory period.

The 18-year-old was with the standby squad a couple of days ago and had been training in the Future Matildas program in Sydney.

Earlier this year, she captained the Westfield Young Matildas in Myanmar and helped them qualify for the 2019 AFC U-19 Women's Championship.

Roestbakken plays her football in the Westfield W-League with Canberra United and coach and former Matilda Heather Garriock was delighted with the news and felt she deserved the opportunity.

"Karly was consistently one of our best players this past season, so to see her get this call up is really great news," Garriock said.

"The injury to Alleway is a big shame and I wish her all the best, but I look forward to seeing Karly take this incredible chance with both hands."

Football runs in Roestbakken's genes as her brother plays for the Monaro Panthers while Jack used to play in the second division league in Norway.

Just like most of our footballing stars, she started kicking a football in her backyard and the former Monaro Panther who was coached by her father Jack Roestbakken for a couple of years said he was very proud of her daughter.

"The thing that stands her out from the rest is her stamina and never say die attitude," Jack said.

"She tries to win the ball at all costs and is determined to drive towards goal."

A spokesperson from the Panthers said "as a club, we are incredibly proud that she started with us and that her brother, Sam continues to play with us in our men's first grade side."

The Matildas start their 2019 FIFA Women's World Cup campaign against Italy on Sunday night from 9pm at Stade du Hainaut.