Former England lock Mouritz Botha has been forced to retire from playing due to a concussion suffered at the end of last season.
The 35-year-old Newcastle Falcons second row has made the decision on medical advice, and will now pursue a career in coaching.
South Africa-born Botha won 10 Test caps for his adopted country, and lifted the Aviva Premiership title with Saracens in 2011. He joined Newcastle two years ago having played Super Rugby with the Sharks in 2015.
"Although many players have mixed emotions when they call time on their playing days, I only have one overriding feeling -- that I was truly blessed to have had enjoyed my time as a rugby player as much as I have done," he said in a statement released by the Falcons.
"I am extremely proud to have been able to represent England, an honour that I will always cherish, and to have won the Premiership with Saracens. Most importantly I have made some fantastic memories and friends for life at all the clubs I have played for along the way and I'll always be indebted to the many people who helped me enjoy such a fantastic journey.
"I was very lucky to learn from some amazing coaches who turned me from a semi professional into an England international. It is for this reason I'm am now pursuing a career in coaching. I want to give players the same experience that I had."