Scarlets fly-half Stephen Jones will equal Gareth Thomas' record of 100 Wales caps if he is picked to face the Barbarians on Saturday, 4 June.
The Welsh Rugby Union have made the Millennium Stadium match a full-cap international to mark the body's 130th anniversary fixture.
With James Hook unavailable for the game as he is getting married, it opens the way for Jones to play.
Caps have been awarded twice before by Wales against the Barbarians.
The first was in 1990 and second in 1996, the latter seeing Cardiff Blues flanker Martyn Williams win the first of his 98 caps.
"We are delighted to announce that Wales will award full caps for this important and historic fixture," said WRU chairman David Pickering.
"The game represents the continuation of a proud history of encounters which have featured some amazing rugby down the years."
After the Barbarians game, Wales coach Warren Gatland will then begin looking ahead to three World Cup warm-up fixtures in August - against England home and away, then Argentina in Cardiff.
The deadline for World Cup squad announcements is 22 August, with Wales launching their tournament campaign against reigning world champions South Africa in Wellington, New Zealand on 11 September.
"The first thing for the squad players to do is impress us physically and in rugby terms on the training camps, then the opportunity comes against the Barbarians," said Gatland.
"I am delighted at the schedule of warm-up fixtures we will be playing. It is important for us to measure our progress against some top-class opposition.
"These matches will be our final games on home soil, the last chance for the players to impress before World Cup selection, which must be completed 48 hours after we face the Pumas, and our final chance as coaches to make some tough decisions."