Kieran Read will walk away from the All Blacks after this year's World Cup, and take up a short stint in Japan.

Read, 33, has played 118 tests in the black jersey and has captained the team in 49 tests.

Former All Blacks captain Richie McCaw told Mike Hosking he knows from personal experience when the right time to walk away from the game is and it's not a decision which is taken lightly.

"It becomes obvious when it feels right to leave but it's certainly not an easy decision. The next step is quite a tough one, it takes a while to get everything sorted.

"He has been around a while and his body has taken a good battering. With the World Cup in Japan this year, it makes it an easy endpoint. Once you make this type of decision, it makes it easier to focus on playing rugby."

When asked if he thought the All Blacks could be under pressure following Read's departure, McCaw said he was confident of the young talent coming through the system, saying all teams go through a transitioning period, especially after World Cup years.

"The great thing in NZ is that we have a lot of players putting their hands up. Sometimes you just need to give the younger players a chance, all they need is an opportunity to prove themselves."

Read was part of the victorious 2011 and 2015 teams and was named World Player of the Year in 2013.