The Lions have drafted former Wales wing Shane Williams into their team for Tuesday's clash against the Brumbies in Canberra.
Williams, Wales' record try-scorer, is currently playing in Japan after retiring from international rugby.
The shock call-up sees him feature in a team that also includes England backs Christian Wade and Brad Barritt, who have been called up as injury cover. Neither player has yet arrived in Australia.
The Lions will be captained on Tuesday by Ireland hooker Rory Best.
The Lions are currently unbeaten on tour, having won five successive games, with the Brumbies clash their final fixture before facing Australia in next week's first Test.
Speaking about Williams' selection, Lions head coach Warren Gatland said: "We said we needed him for one game. He is already on his way here.
"We spoke to Shane and said the proviso is he comes into the squad on Monday and leaves the squad on Wednesday. He is happy with that."
There is also a first start on tour for Ireland full-back Rob Kearney, while Scotland's Stuart Hogg makes his second start of the trip at fly-half.
Lions team to play the ACT Brumbies in Canberra on Tuesday:
R Kearney; C Wade, B Barritt, B Twelvetrees, S Williams; S Hogg, B Youngs; R Grant, R Best (capt), M Stevens, I Evans, R Gray, S O'Brien, J Tipuric, T Faletau. Replacements: R Hibbard, A Corbisiero, D Cole, G Parling, D Lydiate, C Murray, O Farrell, S Zebo.
"We spoke to Shane and said the proviso is he comes into the squad on Monday and leaves the squad on Wednesday," - Warren Gatland
Williams was a Test Lion in 2005 and 2009, but his selection for Tuesday's game comes as a huge surprise. He currently plays for Mitsubishi Dynaboars in Japan.
He scored 58 tries in 87 Tests for Wales. His last international appearance was against Australia in December 2011, when he scored in the last play of the game.
He then featured for the Barbarians against Wales in 2012, having signed off for the Ospreys with two tries in the RaboDirect PRO12 final against Leinster a week earlier.
He is now in his second season in Japan, and he is due to work with talkSPORT on the Lions Test series.
Wade, meanwhile, was withdrawn from England's second Test team in Argentina to make the flight to Australia, while Saracens centre Barritt will arrive from America. He was rested for England's trip to South America.
A third England player - centre Billy Twelvetrees - has touched down in Australia from Argentina, and he will partner Barritt in midfield on Tuesday.
In the forwards, lock Richie Gray returns from a shoulder injury.
The Lions are sweating on the fitness of some key players prior to tackling the Wallabies.
Juggernaut Wales wing George North reported a tight hamstring during last Tuesday's game against a Combined Country XV in Newcastle and has not played since.
Centre Jamie Roberts, meanwhile, suffered a leg injury late in the 47-17 victory over New South Wales Waratahs yesterday.
Gatland is due to announce his Test team next Thursday. The Lions have not won a Test series since they beat South Africa 2-1 in 1997.