A combined New Zealand and Australia XV will face the British and Lions in an unofficial fourth test of the historic side's 2025 tour.
The Lions released their nine-match schedule for the tour of Australia, which includes games against Super Rugby sides, Wallabies, and an invitational Anzac outfit.
The match against the combined XV will serve as the final hitout for the Lions before they embark on their three-test against the Wallabies.
It will take place at Adelaide Oval on July 12, a week before the series opener at Suncorp Stadium.
"The British & Irish Lions Tour is one of the great sporting festivals - it is a real landmark of Australian and world sport," Rugby Australia CEO, Phil Waugh.
"Rugby Australia is looking forward to welcoming back the Lions for the first time in 12 years - as well as the tens of thousands of Lions fans from the northern hemisphere.
"It is an exciting fixture of matches all around the country with the Lions taking on our Super Rugby franchises, three massive test matches, and a marquee match in Adelaide featuring a combined invitational Australia-New Zealand side."
But fans will have to ease expectations of potentially seeing Ardie Savea and Michael Hooper run alongside each other, with the July test window likely to rule many stars out.
With All Blacks and Wallabies commitments coming first, the team will most likely feature the "next best" and for those who missed out on higher honours.
However, it could open the doors for the likes of Richie Mo'unga and other New Zealand internationals plying their trade overseas, who will be ineligible for All Blacks selection.
