Scarlets prop Iestyn Thomas has been forced to retire on medical advice because of a neck injury.
The Wales international has been struggling with the problem he picked up at the start of this campaign.
"The advice I have been given by the surgeons is that I have to retire from the game," said Thomas.
"It's not easy to have to give up my rugby career but my neck injury is such now that it really is impossible to carry on."
The 35-year-old will retire after a decade with the Scarlets.
Thomas, who was capped 33 times by Wales, has been the cornerstone of the Scarlets pack for the last 10 years and has played 214 times for the region.
"Ironically for me, I have been really enjoying playing some of the best rugby of my career in the past two seasons and it's really difficult to let go of that now," he said.
Thomas was appointed vice-captain for the Scarlets and is one of three players in the squad with more than 200 appearances. The others are Stephen Jones (315) and fellow prop Phil John (229).
He joined the Scarlets in 2002 and played for Wales in the 2003 Rugby World Cup after making his debut in his country's victory against Samoa in 2000.
Thomas, who has been celebrating a benefit year during the 2011-12 season, is confident he leaves the Scarlets on the brink of an exciting new era.
"That spirit in Scarlets rugby is still really burning - the young boys coming through have been an inspiration and energised us as senior players," said Thomas.
"It's been great to be part of and watch some of these new generation of Scarlets push forward this season both in a Scarlets jersey and in the international set-up."
Scarlets head coach Nigel Davies paid tribute to Thomas's contribution and influence on his young squad at Parc Y Scarlets.
"Iestyn has been immense for us," said Davies
"To have such an experienced and trusted professional in your ranks with so many younger players is something that as a coaching set-up you really appreciate and rely on."