Competing against Simon Shaw has convinced Brad Thorn that he can make it to 2011. Photo / Getty Images Expand

Competing against Simon Shaw has convinced Brad Thorn that he can make it to 2011. Photo / Getty Images

Brad Thorn will head home today but the 34-year-old is not of a mind to end his career any time soon.

Knowing when to retire is one of the hardest calls a professional sportsperson has to make and Thorn has given the issue plenty of thought. It's a subject that comes up often with the All Black lock as he's played professionally for almost 20 years.

He's ticked a lot of boxes in both rugby and league. His body has been pounded for two decades and he's reached an age where people will ask repeatedly how much longer he has.

Thorn doesn't know the answer. His contract has been signed through to 2011 and all he can say in regard to whether he can make it that far is that at this stage, he wants to.

"I have little things that I keep my eye on, which is my passion and hunger and how hard I'm prepared to work," says Thorn. "When I say how hard I'm prepared to work, I'm talking about first day at pre-season.

"I am always striving for excellence and I know it only comes through hard work.

So if it starts to wane ...

"I usually start my own training two or three weeks before I start with the franchise - so how hard am I pushing myself is a question I ask.

"Hunger, how the body is feeling - all those sorts of things, I keep an eye on. So far I can say that I'm as hungry as anything and my body feels great. Basically, the only reason I would retire now would be because it's common at this age for people to do so. It would just be for the sake of it but I still have goals and things I want to achieve."

The refusal to accept anything less than excellence and total commitment has always been the Thorn way. He made world headlines in 2001 when he turned down the chance to tour with the All Blacks as he was unsure he was going to stay with rugby.

His level of commitment is best explained this year by the fact that, prior to this morning's test, he has played every minute of every test bar the Milan clash with Italy. That's a phenomenal record and one of which he is not only proud, but one that has helped him play the best rugby of his career.

All Black coach Graham Henry said of Thorn last week: "He's an inspiration to the whole squad. I think he's playing the best football of his career and becoming a world-class lock."

It was an assessment with which All Black captain Richie McCaw agreed. Thorn has been extraordinary in his ability to raise the game in the final quarter of every test he plays. While some players are gasping for air and starting to hit the wall, he finds another dimension.