Boyle, who captained the Newcastle Knights to their maiden NRLW premiership on Sunday, has chosen to prioritise her new business Trainer Group which helps facilitate workshops which aim to help people with disabilities gain new skills to help in the job market.

She announced her decision to withdraw from the team on social media on Tuesday.

"Unfortunately, due to my work commitments with Trainer Group, it isn't possible for me to be away for the period of time required overseas," she said.

"This year has been amazing presenting our inclusive programs across the NRL, but a challenge juggling football commitments at the same time.

"I will therefore be using the off-season to work on new programs and planning out a massive 2023 for our participants.

"I am obviously upset I won't be able to experience the World Cup, but will be cheering on the girls every step of the way."

Boyle's coach at the Newcastle Knigihts, Ronald Griffiths, told nrl.com he was "fully supportive" of Boyle's decision.

"Millie is all about team-first actions, and putting her business and her participants' needs ahead of her playing ambitions is the very epitome of team first," he said.

"No doubt sitting out a World Cup is one of the hardest decisions a player will make in their career."

Bega junior Kezie Apps will make the trip to England for the World Cup as one of the co-captains of the Jillaroos side.

It will be Apps' second World Cup appearance after she was part of Australia's winning squad in 2017.

The Jillaroos will play the Cook Islands, France and New Zealand in their round robin games in York in the United Kingdom.