England's World Cup-winning captain Katy Daley-Mclean will retire from playing after appearing for a star-studded women's Barbarians team in the club's first 'double-header' game.
"The opportunity to go back to Twickenham and play one more time, in the black and white hoops, nothing will top that. It is one last time," the 35-year-old fly-half told BBC Sport.
The Barbarians women's side play a Springbok women's XV at 17:15 GMT at Twickenham after the men's team have played Samoa at the same venue.
South Africa hooker Malcolm Marx, Australia fly-half James O'Connor and former Ireland and British and Irish Lions full-back Rob Kearney are in the men's squad.
Ryan Wilson, who won the most recent of his 50 Scotland caps in March's win away in France, is included as a back-row option along with Springbok Duane Vermeulen.
Argentina's sevens star Marcos Moneta, who was the top try-scorer in the men's tournament at the summer's Olympics, is an exciting backline option for coach Dave Rennie.
Daley-Mclean retired from the international game in December, having won 116 caps, but has been coaching and occasionally playing with Premier 15s side Sale Sharks since April 2020.
"I remember being 11 or 12 years old and buying a Barbarians shirt," she said.
"[Playing for them] was one of those things you didn't dream of because it didn't exist. It was all famous names in the men's game going off to play in this epic free-flowing style and the women just didn't do it.
"To be asked is a massive honour. I have done some amazing things in my career, but this is really unique."
Prop Rochelle Clark, England's most-capped player in either the men's or women's game, is also part of the squad along with Bristol's free-running front row Simi Pam and out-going Ireland captain Ciara Griffin.
Natasha Hunt, part of England's 2014 World Cup success alongside Daley-Mclean, and Ireland centre Sene Naoupu are available to Worcester Warriors women's director of rugby Jo Yapp, who is coaching the side.
"Our preparation is all about getting to know each other, blending personalities and playing styles and ensuring every player has the chance to express themselves," said Yapp.
The Barbarians women's team played for the first time in 2017 and this will be their first match since beating Wales in November 2019.
The men's team were due to play England in October 2020 but the fixture was called off after a number of Barbarians players breached Covid protocol.