Lyndon Bateman has been with the Ospreys since their inception in 2003
Ospreys second row Lyndon Bateman has retired at the age of 31 after losing a long battle with a knee injury.
"It's with great sadness that I admit defeat to the injury that has plagued me for 16 months," said Bateman.
"After such a long period of recovery and rehab with no near return in sight, it has become apparent that I will not be able to make my desired comeback."
Bateman dislocated his knee playing in the Welsh Premiership for Aberavon against Pontypool in January 2009.
Bateman has been with the region since its inception in 2003, having previously played for Neath.
I'm leaving my dream job, and I'm stepping back into the real world once again
He has made 79 appearances for the Ospreys, scoring two tries, helping them to two Celtic League titles and their 2006 win over Australia.
His final appearance for the Liberty Stadium side was against Munster in January 2009.
"I'm leaving my dream job, and I'm stepping back into the real world once again," said Bateman.
"I'd like to wish the Ospreys all the best for the coming season and the future beyond."
Ospreys elite performance director Andrew Hore added: "It is always a terribly sad thing when a playing career is cut short because of injury, so we all feel for Lyndon who has had to face up to this reality.
"A tremendous servant to the Ospreys since our inception, he is a fantastic character who has always brought so much to the environment."