Irish great O'Callaghan to hang up boots
The 38-year-old lock was an integral member of the Ireland side that memorably won the 2009 Six Nations Grand Slam and is currently playing for Worcester Warriors, having retired from international rugby four years ago.
"It's been great. I have had a great time. I love the game and I want to finish loving it," he told The Irish Examiner.
"Honestly, body wise I feel great. The game is changing though and everyone is talking about it this season.
"Over the last three years, the physicality has gone through the roof.
"I'd love to be able to walk away from it and say I had a great time within it and be thankful to the game itself."
O'Callaghan, who formed a legendary second-row partnership with Paul O'Connell both for province Munster and his country, will see out the season captaining English Premiership side Worcester.
Aside from the Grand Slam triumph, 94-times capped O'Callaghan also won the 2004 Triple Crown and two European Cups with Munster, as well as being selected for two British and Irish Lions squads (2005/09).
Agence France-Presse