Veteran flanker Martyn Williams will face Wales for the Barbarians in June, in all likelihood pitting him against his Test successor Sam Warburton.
Wales coach Warren Gatland overlooked 35-year-old Williams in Warburton's favour for the Six Nations.
But Gatland has stated Williams' Barbarians involvement does not rule the player out of World Cup contention.
It's something special to be playing for them [Barbarians] against your home country," said Williams.
Barbarians coach Dai Young - Williams' Cardiff Blues boss - will also have also have Italy's star number eight Sergio Parisse and Australian back-row legend George Smith in the squad to face Gatland's side on a day when Wales' players will be awarded caps.
Gatland said: "Playing for the Barbarians does not exclude Martyn from the opportunity of still being selected for our World Cup squad.
"With Martyn in the opposition line-up, it's a great chance for us to see how our young back row will cope in an international match against such an experienced and world class player."
Williams, who has won 98 Wales caps, said: "Hopefully, if I can put in a good performance, I can get back into Warren's plans for the World Cup.
"Having spoken to Warren, I know it's a case of the more Welsh players on the field the better.
"The coaches know what I can and can't do, but it will be a fantastic occasion and I can't wait to run out at the Millennium Stadium against boys I've played with there so many times.
"I would love to go New Zealand, the Rugby World Cup is the pinnacle of anyone's international career, along with the British [and Irish] Lions.
"If I was asked to go, I would grab the opportunity with both hands but there is a lot of rugby to be played before then with the end of the Magners League and the summer internationals.
"And the one place we [Wales] have a lot of strength in depth is in the back row.
"I will just keep going for the Blues and see what happens."
Williams admits it will be "strange" to face Wales but is looking forward to returning to the Millennium Stadium, where he last played in their 37-25 defeat by New Zealand in November 2010.
Williams could line up alongside three World Cup winners.
South Africans Francois Steyn and Ruan Pienaar joined England's Iain Balshaw as Baa-Baas coach Dai Young named the first six players in his squad.
Wallaby Smith and Ireland prop John Hayes have each won more than 100 caps.
Wales' veteran fly-half Stephen Jones expected to join the nation's cap record-holder Gareth Thomas on 100 caps during the game.
The fixture is being staged to help the Welsh Rugby Union celebrate its 130th anniversary and marks the beginning of Wales' 2011 World Cup preparations.
Warren Gatland's side will go on to play three Tests in August - two against England and one against Argentina - before heading to New Zealand.
Steyn and Pienaar helped the Springboks win the World Cup in 2007 in France, while Balshaw won a winners' medal in England's 2003 triumph in Australia.
The South African duo could also be part of their 2011 campaign to retain the crown - and they face Wales in the pool stages in New Zealand.
Their pool also includes Samoa, Fiji and Namibia.
Barbarians squad (to be finalised):
Francois Steyn (Racing Metro, Paris/South Africa), Ruan Pienaar (Ulster/South Africa), Iain Balshaw (Biarritz/England), George Smith (Toulon/Australia), John Hayes (Munster/Ireland), Sergio Parisse (Stade Francais/Italy), Martyn Williams (Cardiff Blues/Wales).