Former Scotland captain John Barclay announced his retirement as a player on Saturday saying he is "eternally proud" to have skippered both his country and Welsh region Scarlets.
The 33-year-old Hong Kong-born backrow forward - capped 76 times and who appeared at three World Cups - explained his decision saying "you know when you know."
Barclay had been without a club since leaving Edinburgh earlier this year - he retired from Test rugby after last year's Rugby World Cup when Scotland exited in the pool stage.
"When you know, you know," Barclay said in a post on Instagram.
"I never wanted to get to the point where I was playing for the sake of it.
"Physically I could have kept going for a little while, but at nowhere near the level I wanted.
"The body has had enough, and the mind is ready to move on to the next step."
Barclay, who won the 2017 Pro12 title with the Scarlets, played in the 2007, 2011 and 2019 World Cups and his high point as captain came with the 2018 Calcutta Cup 25-18 victory over England.
It was the Scots' first win over their opponents in a decade.
"To get capped was beyond my wildest dream as a kid growing up," he said.
"To be able to go on and captain Scotland and Scarlets is something I will be eternally proud and grateful of.
"Knowing I wont get the chance to run out with the team does leave a tinge of sadness, but I was a supporter before I was a player, and I will be a fervent supporter again."