Head coach Steve Borthwick has named a 36-player squad for the tournament, assembling at Pennyhill Park on Monday. In the absence of Mitchell, Bath scrum-half Ben Spencer and Bristol Bears' Harry Randall have been called into the setup as scrum-half options alongside Leicester Tigers player Jack van Poortvliet.

Mitchell sustained the injury during Northampton's 28-14 win at Franklin's Gardens, leaving the pitch after just 21 minutes. The 29-year-old has established himself as the first-choice number nine under Borthwick, making his prolonged absence a significant blow to England's preparations.

Compounding the scrum-half shortage, uncapped Northampton player Archie McParland is also sidelined after sustaining a calf injury during training with the national squad last week. Consequently, Borthwick faces a major reshuffle in the half-back department ahead of Sunday's opening fixture against the Wallabies.

Van Poortvliet, who started all three of England's summer Tests, is widely expected to wear the starting shirt at Allianz Stadium. Both Randall and Spencer offer contrasting strengths from the bench, with Randall renowned for his sniping running game and Spencer valued for his tactical kicking.

In other squad news, fly-half Fin Smith took a limited part in training upon arrival as he continues his recovery from a calf problem. England coaching staff remain optimistic about his availability for Sunday's encounter, though Harlequins playmaker Marcus Smith is also pushing for the starting fly-half berth.

Several other players are managing injuries within the 36-man group, including hooker Luke Cowan-Dickie and flanker Tom Curry. Both participated in modified training sessions at the Bagshot base but are expected to be fit for selection by the end of the week.

Borthwick's squad features 20 forwards and 16 backs as England return to Allianz Stadium for four consecutive Test matches. Following Sunday's clash with Australia in round four of the competition, England will host Japan in round five and New Zealand in round six.

The autumn series concludes with the finals weekend scheduled from November 27 to 29. Borthwick highlighted the importance of the upcoming matches, noting they provide a final opportunity to face southern hemisphere opposition before next year's Rugby World Cup.

"We're looking forward to getting back to Allianz Stadium for four important Test matches against top-level opposition," Borthwick said. "These fixtures take on added significance this autumn as they represent our final opportunity to face southern hemisphere opposition before next year's World Cup."

England squad: Forwards: Fin Baxter, Ollie Chessum, Arthur Clark, Alex Coles, Luke Cowan-Dickie, Ben Curry, Tom Curry, Theo Dan, Ben Earl, Greg Fisilau, Jamie George, Ellis Genge, Joe Heyes, Maro Itoje, Emmanuel Iyogun, George Martin, Asher Opoku-Fordjour, Tom Pearson, Henry Pollock, Will Stuart. Backs: Seb Atkinson, Fraser Dingwall, Immanuel Feyi-Waboso, George Ford, Tommy Freeman, George Furbank, Will Joseph, Joe Marchant, Cadan Murley, Harry Randall, Henry Slade, Fin Smith, Marcus Smith, Ben Spencer, Freddie Steward, Jack van Poortvliet.

The encounter marks the first meeting between the two nations since a difficult 90-4 defeat for England in Las Vegas in March 2025. That previous result, which saw Australia score 17 tries, served as a sobering experience for the English squad.

England head coach Stuart Barrow has emphasised that his current group is vastly different from the one that played in Nevada. Only six players from that previous squad remain, with a new, youthful dynamic defining the current selection.

Barrow expressed confidence in his players ahead of the match, stating that the squad is approaching the game with excitement rather than fear. He believes the younger members of the team are eager to test themselves against the world's best.

The England camp has been bolstered by a strong start to the tournament, having defeated Wales 70-6 in their opening fixture. Despite the win, Barrow noted that the team must improve their ball retention and reduce unforced handling errors.

Preparation for the clash with Australia has been impacted by the loss of Jasmin Strange, who suffered a serious knee injury in training on Tuesday. The Sydney Roosters second-row forward has been ruled out for the remainder of the tournament.

Australia, who have dominated international rugby league and lost only once since 2016, began their World Cup campaign with a 40-0 victory over Samoa. They remain the benchmark for the sport at the international level.

Australian hooker Keeley Nizza acknowledged the rivalry between the two nations but insisted that her team is not underestimating the opposition. She noted that England has evolved significantly as a side since their last meeting.

England’s squad features several standout performers, including debutant centre Connie Boyd, who scored a hat-trick against Wales. The team also includes 19-year-old Woman of Steel Jenna Foubister and her Wigan team-mate Isabel Rowe.

Isabel Rowe made a significant impact in the opening match, scoring 26 points, the highest tally by an England female player in a single World Cup game. Her partnership with Foubister has been described by Barrow as telepathic.

Winger Amelia Brown has also drawn attention after a viral performance against Wales, which included a 107-metre try. Barrow praised the 22-year-old’s debut, noting the positive impact such moments have on the visibility of the women's game.

Barrow remains focused on the tactical challenge posed by Australia, stressing the importance of respecting possession. He stated that while the past defeat is buried, it has provided valuable lessons for the team's development over the last 18 months.

The England coach confirmed that senior players who were involved in the 2025 match have been sharing their experiences with the younger squad members. This peer-to-peer learning is intended to help the team navigate the pressures of the tournament.

The match is scheduled to kick off at 10:05 BST on Saturday. It will be broadcast with live commentary available on BBC Radio 5 Sports Extra, the BBC Sounds platform, and the official BBC Sport website and app.

As the tournament progresses, the result of this fixture will be crucial for both teams' standings. England are aiming to demonstrate their growth and competitiveness against a side that has historically held the upper hand in international rugby league.

The atmosphere in Perth is expected to be intense, with both teams looking to secure a vital win. For England, the focus is on executing their game plan and maintaining focus throughout the full 80 minutes against the Jillaroos.

The tournament serves as a platform for the growth of women's rugby league globally. Both Barrow and the players are aware of the opportunity to showcase the sport to a wider audience through high-quality performances on the field.

With the injury to Strange, the depth of the England squad will be tested. However, the coaching staff remains confident in the ability of the remaining players to step up and perform under the pressure of a World Cup environment.

The match represents a pivotal moment for England as they seek to establish themselves as genuine contenders on the world stage. A strong performance against Australia would be a significant statement of intent for the remainder of the competition.

Fans and analysts will be watching closely to see how the tactical adjustments made by Barrow translate against the world champions. The outcome will likely shape the narrative for the rest of the tournament as the knockout stages approach.