Warren Gatland will hand his hopefuls their first chance to force their way into the squad against Ireland on Saturday.
And that will mean several Test debuts at the Millennium Stadium.
Among those expected to win their first cap is Tomas Francis, just three years after being unable to secure a contract from any of the four Welsh regions.
The 23-year-old Exeter Chiefs prop, who qualifies through his Welsh grandmother, was first invited to train with Wales during the Six Nations.
At the time, he was delighted simply to be rubbing shoulders with established internationals.
But fate is conspiring in his favour and now Francis has a shot at becoming a starter at the World Cup.
He has clearly impressed during the ‘brutal’ Welsh training camps in Switzerland and Qatar.
Forwards coach Robin McBryde, below, told TRP: “Tom hadn’t experienced anything like those camps before but raised everyone’s eyebrows with the way he has dug deep.
“Set-piece is obviously a big strength for Tom but he’s more than holding his own around the pitch and with all the rest of the stuff.
“He’s already a different player and it’s exciting to see what he can do during the warm-up games.”
Wales have lost Adam Jones through retirement and Rhodri Jones to a torn pectoral muscle.
And with Samson Lee rated “touch and go” by Gatland for the World Cup, and almost certain to miss at least the opening game, the door is open for Francis to not only stake a claim for a place in the squad, but even start against Uruguay on September 20.
Fellow front-row, hooker Ken Owens, below, said: “Tom has really worked hard on his conditioning and is looking good. He’s impressed everyone. It would great for us to have Samson fit for the World Cup but Tom is among others who are really putting their hands up this summer.”
Ross Moriarty is another who is set to face Six Nations champions Ireland on Saturday while Eli Walker and Gareth Anscombe are also poised to win their first caps as Gatland uses the opening match of their pre-World Cup schedule to hand the fringe players a chance to impress.
McBryde said: “The conditioners have been sorting the wheat from the chaff as they push the players to their limit during training.
“We’ve pitted guys in the same positions against each other as a means of bringing out the best in them. At times we’ve just been able to sit back and watch them go for it because they all know they have to impress.
“There’s very little between any of them from a fitness point of view and ultimately it will come down to a rugby decision, based on the next few weeks.”
MATT LLOYD