Matthew Rees was on Wednesday ruled out of contention for Wales' Six Nations opener against Ireland after suffering a calf strain.
Rees, who was vying for a starting place along with World Cup hooker Huw Bennett, may also miss Wales' second championship game against Scotland next week.
Bennett now seems certain to win his 50th cap when Wales line up against Ireland in Dublin on Sunday.
With Rees missing, Scarlets teammate Ken Owens is favourite to earn a place on the bench.
Wales' preparations for the Six Nations have been disrupted by a string of injuries to key players, with centre Jamie Roberts, flyhalf Rhys Priestland and flank Dan Lydiate all battling to be fit.
Prop Gethin Jenkins and World Cup locks Luke Charteris and Alun-Wyn Jones have already been ruled out of contention as Wales coach Warren Gatland prepares to name his team on Friday.
AFP
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.