Iestyn Harris has ruled himself out of Wales' summer tour to Argentina and South Africa.
Cardiff Blues' former rugby league star is nursing a knee injury, and needs a minimum six weeks' rest.
Wales play a two-Test series against Argentina on June 12 and 19, followed by an appointment with the Springboks in Pretoria on June 26.
It is another blow for new Wales coach Mike Ruddock, with shoulder problems set to sideline Llanelli Scarlets forwards Robin McBryde and Dafydd Jones, while half-backs Stephen Jones, Gareth Cooper and Ryan Powell are all battling to prove their fitness.
In addition, Celtic Warriors lock Robert Sidoli and his team-mate, full-back Kevin Morgan, also face a race against time to be fit.
Ruddock had planned to announce his squad on Thursday, but that has now been put back until early next week following the final round of Celtic League games.
"I am pretty devastated to be ruled out. I had earmarked the tour to really make a claim,'' said Harris.
"I've got severe bruising in the shin and quad bones, and I've also got a tear in the posterior cruciate ligament.
"It has been an extremely long year, with the World Cup. We've been playing international rugby since July last year.
"There is only so much a body can take at that level, and over the next two or three weeks, you will see plenty of players dropping out of tours - not just for Wales, but for every country that's going on a tour,'' Harris told BBC Wales Sport.
As head coach Stuart Lancaster polishes the axe he will soon wield over his World Cup training squad, Exeter Chiefs coach Rob Baxter has backed Jack Nowell, Henry Slade and Luke Cowan-Dickie to be given a stay of execution.
Italy Under-20s held off a late Samoa blitz to retain their place in the World Rugby U20 Championship on Saturday and head coach Alessandro Troncon believes the experience will have served as a valuable lesson for his young troops.