And the 35-year-old, whose just needs two more caps to reach a century of appearances for Wales, knows the stage is set for him to make his point to coach Warren Gatland.

He said: “It sounds strange to be playing against Wales for once but I’m really looking forward to it.

“It will be great to be back at the Millennium Stadium. It’s been a while since I’ve played there now and I’ll get to play against a lot of my friends which will be exciting.

“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.

“I would love to go New Zealand, the Rugby World Cup is the pinnacle of anyone’s international career, along with the British Lions. If I was asked to go, I would grab the opportunity with both hands.”

And while Williams will be on the outside looking in on June 4, Gatland confirmed he is still very much in their plans.

He 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.”