The Lions suffered an alarming casualty rate during a brutal tour that reached its bone-crunching climax during the Test series, including the loss of talisman Brian O’Driscoll, underlining rugby's increasing physicality.

Player welfare is now a critical issue and Fitzpatrick expects careers to become shorter as the hours spent in the gym continue to challenge the body's limitations.

"The game is so much more physical now because players have more time to get bigger and stronger. Where it will end up I don't know," said the former New Zealand skipper on behalf of 'Laureus - Breaking the Cycle of Violence'.

"They're big guys so people will get hurt. The knock-on effect is the life span of a professional rugby player will become a lot shorter than what it was.

"Even now professional sportsmen playing international rugby at 28 are considered old. In my day if you were 34 you were coming to the end. It's only going to get worse."