New Zealander Christian Cullen has retired with immediate effect.
Cullen in action against Scarlets in the Heineken Cup in March
The 31-year-old full-back, who played his last game for Munster last month, said injury problems were the main reason for his decision.
"I've hung up the boots for good," he said. "My mind is fresh and feels like I could sign another four-year deal.
"But there comes a time when you have to be a realist and I know my body has had enough. I can't remember the last time my ankles and knees didn't ache."
He added: "At the back of my mind I'm always worried that I might be a tackle away from injuring the shoulder again.
"So, in the end, it's an easy decision to retire. I will miss a lot of things about the game but I can't sign a new deal knowing my body has had it."
Cullen is the All Blacks' all-time record try-scorer in Tests with 46 in 58 appearances.
He joined Munster four years ago after being left out of the World Cup and scored 14 tries for the club, but only played 44 matches because of injury.
"I have loved every minute of my time in Ireland - apart from the injuries," he said.
"The club and supporters have been terrific to me but I can't help feeling that I have let them down.
"When I signed in 2003 I felt like I could reproduce the type of performances I was able to put on for the All Blacks but three shoulder operations put paid to that.
"Munster will always hold a special place within me. The toughest thing about retiring is walking away from Thomond Park.
"I just wish I could have done more for the club, my team-mates and Munster's great supporters."
Cullen is moving back to New Zealand in August to pick up business interests.