Swansea half-back Gavin Henson, Bath scrum-half Andy Williams and Newport pair Andy Powell and Hal Luscombe have all ruled themselves out of the Under 21 World Cup which commences for Wales against Italy in Johannesburg's Ellis Park next Thursday.
The prodigious Henson was expected to be named as part of coach Chris Davey's 26-strong squad but the 20 year-old has surprisingly ruled himself out - handing the Wales number 10 jersey to rival Nicky Robinson.
Davey confirmed, "Gavin has made himself unavailable for the World Cup, we are not really sure why.
"He has not had the best of seasons although he started the Six Nations Championship in good form for us, I only hope that the added competition for places at Swansea next season will bring out the best in him."
The Welsh World Cup campaign has also been denied the services of up-and-coming Newport no 8 Andy Powell who feels he needs to rest after a demanding season.
Bath scrum-half Andy Williams and Newport centre Hal Luscombre have also declined the offer of a place.
However Davey is confident the side can live up to expectations.
"Having been seeded fourth we have to target a top four finish," he added.
"The boys have tried and tested themselves at Six Nations level and proved they can compete very well. This will be another step up from that and will be a very good experience. The opening game against Italy should be a good one to get us going."
After the Italian game, Wales take on Argentina on Tuesday June 18 with their final game against favourites New Zealand on Friday June 21.
The team will be skippered by Swansea's Matthew Bayley.
Wales Under 21 World Cup squad:
G Swayles (Swansea), M Nuttall (Pontypridd), K Morris (Caerphilly), L Roberts (Cardiff), N Jones (UWIC), M Jones (Neath), M Bayley (capt, Swansea), S Williams (Newport), N Robinson (Cardiff), M Hook (Newport), M Phillips (Llanelli), C Miller (Cardiff); P James, A Jones, P Matthews (all Neath), C Jones (Llanelli), M Miles (Northampton), G Morris (Pontypridd), B Griffiths (Llanelli), L Tait (Cardiff), L Charteris (Newport), R Jones (Bridgend), R Williams (Ebbw Vale), G Williams (Llanelli), R Sowden-Taylor (Cardiff), R Jones (Newport)
Llandovery are aiming to make it three titles in a row in this year's Foster's National 7s being held at BT Sport Cardiff Arms Park on Sunday 28 August. Drovers assistant coach Simon Davies and Lee Rees assess their sides chances
A pioneering strength and conditioning programme has been delivered to more than 8000 boys and girls at hub schools throughout Wales this season, helping to develop stronger, more flexible athletes for rugby and other sports.
The Singha Premiership Rugby 7s Series returns to the BT Sport Cardiff Arms Park on July 22nd when all four Welsh regions go head to head. Scarlets skills coach Dai Flanagan and Blues Elite Performance Pathway Manager Richard Hodges along with current Welsh squad members were at the launch of this season's event
GB7s women left their England base to train in Wales this week. Olympic Games hopeful Rachael Burford gives WRU TV's Graeme Gillespie her thoughts on Welsh teammate Jasmine Joyce - a 'one touch wonder'
The GB7s women's squad is currently training at Wales' Centre of Excellence where assistant coach Richie Pugh tells WRU TV's Graeme Gillespie some 'tough calls' will have to be made when it comes to finalising the 12 spots for Rio's Olympic Games.