All Blacks skipper Richie McCaw has reflected on his long international career and what the future holds, but doesn't plan to play on when he isn't good enough to make the team on merit.

The 31-year-old has another four year's on his contract with the NZRU, but will hang up his boots if he doesn't think he can make it to one last World Cup.

"Four years is definitely a long time, but I'm not going to hang around when I'm not good enough to be here," McCaw told the NZ Herald.

"I will move on before that and hopefully you know when that is."

As players get older they adapt their games and sometimes change position to suit their strengths, but McCaw has no interest in shifting to blindside and still thinks he can improve in the All Blacks No.7 jersey.

"I still believe that I can play better and I think I can evolve as a No.7 too," McCaw explained.

"I've always said I would do whatever's right for whatever team I'm in, but I do think my best position is seven. I can play the other ones and if I have to do that, I have to do that.

"That's why I want to carry on playing, because I still think I can offer something. When I stop doing that, or stop enjoying it, I'll start doing something else."

Budding head coach Steve Hansen, who is widely regarded as the favourite to take over from Graham Henry, is in awe of what McCaw has achieved and what he can still offer the team.

Hansen admits that McCaw might struggle to reach the next World Cup, but does believe he can still offer a lot as far as grooming future leaders in the team.

"If you look at it, can he get to four years? I don't think he knows that and I don't think any of us know that," Hansen said.

"What we do know is that he will be mentoring new leaders because we've already lost some overseas - Brad Thorn and Mils [Muliaina] for example.

"There will be opportunities over the next few years, for sure, to allow others to lead the side.

"Regardless of whether he makes four years or not, Richie will mentor others. He's already passing on things to a guy like Kieran Read at the Crusaders. DC [Dan Carter] is also there and he's vice-captain. It's already happening. It's never been his way or the highway, it's our way."