Wales were forced into two changes to their squad before they departed for the competition which takes place at venues around northern Italy. Blues wing Harry Robinson and centre Adam Warren have been ruled out with ankle ligament and hamstring injuries respectively, with Carmarthen Quins centre Rheon James and Bridgend wing Ross Jones joining the squad from the list of reserve players.
James was capped for Wales Under 20 during the recent Under 20 Six Nations, while Jones, who played for Ireland Under 18 while at school in Dublin, is set to make his Wales debut in Italy.
The other new caps in the squad are utility backs, Bangor-born Iolo Evans, Llanelli's Dale Ford and Dragons outside-half / centre Lewis Robling.
Webster stressed the importance of the tournament for his young charges, declaring: "We are based near Venice which is a beautiful city, but we won't be taking too many gondola rides I can assure you!
"I've been thrilled with the attitude of the boys. They've been going that extra yard in training and we are all raring to go now with our first match on Friday.
"The Argentina game is massive for us and will go a long way to determining how we do in the tournament. I'm sure they'll have a big pack mentality which we will need to front up to that and then hopefully move them about a bit."
After that opening game, Wales play New Zealand on Tuesday 14 June and hosts Italy on Saturday 18 June in their other Pool games before the play-off games to decide final positions which take place in Wednesday 22 June and Sunday 26 June.
Webster added, "New Zealand have never lost a Junior World Championship game so we will have it all to do. That said, we will do our utmost to cause an upset or at least get something out of the game in order to have a good chance of reaching the last four.
"The Junior World Championship is an intense competition with five matches in 16 days and it will give the players an great insight into what it takes to become a professional rugby player. It's going to be tough but we have a good mix of talent throughout the squad, and we will make sure we fly the Welsh flag with pride."
Wales' Junior World Championship squad:
Backs: Liam Williams (Llanelli), Ross Jones (Ospreys / Bridgend), Eli Walker (Ospreys / Swansea), Dale Ford (Scarlets/ Llanelli), Owen Williams (Blues / Cardiff), Rheon James (Scarlets / Carmarthen Quins), Iolo Evans (Scarlets/ Llanelli) Steve Shingler (London Irish), Matthew Morgan (Ospreys / Swansea), Lewis Robling (Dragons/ Newport), Lewis Jones (Blues/ Pontypridd), Jonathan Evans (Dragons / Newport)
Forwards: Rhodri Jones (Scarlets / Llanelli), Lewis Smout (Blues / Pontypridd), Will Taylor (Ospreys / Swansea), WillGriff John (Blues / Pontypridd), Kirby Myhill (Scarlets / Llanelli), Sam Parry (Llandovery), Cory Hill (Blues / Pontypridd), Macauley Cook (Blues / Cardiff), Luke Hamilton (Blues / Glamorgan Wanderers), Lloyd Peers (Ospreys / Bridgend), Edward Siggery (Pontypridd), Thomas Young (Blues / Cardiff), Ben Thomas (Ospreys / Bridgend), Owen Sheppeard (Blues / Pontypridd)
Watch Wales U20 in action (UK time):
Wales v Argentina, Friday 10 June, 17.10 (Padua)
Wales v New Zealand, Tuesday 14 June, 17.10 (Rovigo)
Wales v Italy Saturday 18 June, 17.10 (Treviso)
Play-Off dates: Wednesday 22 June, Sunday 26 June