Jacques Burger has retired from international rugby after he was ruled out of Namibia's last World Cup match this weekend because of concussion.
The Saracens flanker and Namibia captain was concussed nine minutes into the Pool C match against Georgia on Wednesday in Exeter, and will not be able to play against Argentina on Sunday in Leicester.
"It was a huge disappointment that I could not complete last night's match and an even bigger disappointment that I will not be able to play on Sunday," Burger said.
"I am very proud of my team, and it is not the way that you would want to end an international career. But that's the game of rugby for you."
Burger is one of the game's fiercest competitors, overcoming multiple injuries to lead his country into this year's World Cup.
His lung-busting, all-action performance in Namibia's 58-14 defeat to New Zealand has been hailed as one of the best in the tournament.