Players will start to come in for training sessions with Wales on a rolling basis during May, with entry into camp depending on when an individual’s club season has ended.
Wales U20s have two preparation matches ahead of the tournament. On Friday 6 June they will face England at Pontypool Park and on Friday 13 June Wales play Italy at Cardiff Arms Park.
The official 30-player squad to travel to Italy for the Championship, which runs from 29 June to 19 July, will be announced between the two warm up fixtures. Ospreys have two players in the sqaud, with back-row Dan Gemine and fullback Lewis Edwards named.
Tickets to watch Wales U20 in action against England and Italy will be available on the gate priced £5 adults with free entry for under 16s.
Whiffin said: “This 45-man training squad is a mixture of guys that did really well during the Six Nations for us and then the U18s and U19s had a really good block post Six Nations – the U18s went and won all three games out in Vichy and there's a number of those guys that stepped up.
“You also have the culmination of Super Rygbi Cymru - there's boys that have been putting their hand up in the last few weeks in that competition and it gives us an opportunity to put a bit of pressure on the guys that had the jersey in the Six Nations and also prepare for
what guys might step up next year.”
As the players come into camp to prepare for the tournament Whiffin commented: “The next few weeks are going to be really important for the boys. We've put a big focus on our individual skills and individual development.
“They'll be working incredibly hard physically and we've set a mantra for the boys to improve the individual, improve the team.
“We want everyone to come out of this development block, be it whether they get on the plane or not a better player. So there'll be some tough work for them and it'll be fun. But there will be a big focus on being better players at the end of it.
On the two preparation matches Whiffin added: “Our prep's going to be important and those two games against England and Italy will give us a great indication of where we are. We're playing against the world champions in one prep and it’ll be a tough game against Italy as well.
“We're going to use the England game as a selection tool and that will drop us down to our 30 player squad for the World Cup and then the Italy game will be our last opportunity to prepare before we get out to Italy for the tournament and face Argentina.”
Wales training squad for 2025 World Rugby U20 Championship
Forwards (25)
Dylan Alford (Scarlets /RGC)
Harry Beddall (Dragons RFC)
Jake Bowen (Scarlets)
Tom Cottle (RGC)
Ioan Emanuel (Bath Rugby)
Keanu Evans (Scarlets)
Luke Evans (Exeter Chiefs)
Will Evans (Scarlets)
Dan Gemine (Ospreys)
Deian Gwynne (Gloucester Rugby)
Saul Hurley (Aberavon)
Caio James (Gloucester Rugby)
Owain James (Dragons RFC)
Kenzie Jenkins (Bristol Bears)
Ryan Jones (Dragons RFC)
Evan Minto (Dragons RFC)
Jac Pritchard (Scarlets)
Sam Scott (Bristol Bears)
Cerrig Smith (Dragons RFC)
Harry Thomas (Scarlets)
Nick Thomas (Dragons RFC)
Louie Trevett (Bristol Bears)
George Tuckley (Dragons RFC)
Cameron Tyler-Grocott (Cardiff Rugby)
Evan Wood (Pontypool / Cardiff Met)
Backs (20)
Aidan Boshoff (Bristol Bears)
Tom Bowen (Cardiff Rugby)
Rhys Cummings (Cardiff Rugby)
Osian Darwin-Lewis (Cardiff Rugby)
Sion Davies (Cardiff Rugby)
Ioan Duggan (Dragons RFC)
Lewis Edwards (Ospreys)
Steff Emanuel (Cardiff Rugby)
Elijah Evans (Cardiff Rugby)
Harri Ford (Dragons RFC)
Logan Franklin (Dragons RFC)
Carwyn Leggatt-Jones (Scarlets)
Ellis Lewis (Neath)
Lloyd Lucas (Cardiff Rugby)
Elis Price (Scarlets)
Harry Rees-Weldon (Dragons RFC)
Osian Roberts (Sale Sharks)
Dylan Scott (Cardiff MET)
Harri Wilde (Cardiff Rugby)
Jack Woods (Bath Rugby)
WALES WORLD RUGBY U20 CHAMPIONSHIP PREPARATION MATCHES
Friday 6 June: Wales v England
Pontypool Park
KO 15.30
Tickets available on the gate priced £5 adults with free entry for under 16s.
Friday 13 June: Wales v Italy
Cardiff Arms Park
KO 16.30
Tickets available on the gate priced £5 adults with free entry for under 16s.