Retallick, regarded as the game's premier lock, has yet to commit to his future beyond the tournament that wraps up in early November.
Reports have linked him to a $1.9m move to the English Premiership with the Sale Sharks though Retallick has denied that is happening.
He appears to be in two minds but seems keen to continue with New Zealand and a sabbatical may be one answer to keeping him on board.
"In terms of my post-World Cup future, I'm not too sure yet and I'm still sort of working through that. At the conclusion of the World Cup, I will be 28 years old and I would like to think that I still have something to offer the All Black jersey, but I have to work it [my future] out and see how it looks," Retallick told Sport24 in South Africa where he just helped the Chiefs get their season back on track with a stunning 56-20 demolition of the Bulls in Pretoria.
"I have been a part of the All Blacks for a while now and it's been great. It was always a big goal of mine to make the All Blacks and with the World Cup being at the back end of the year in Japan, it's a pretty big."
Retallick is keen to concentrate on getting his Chiefs back into the playoffs mix for now.
"Playing for the All Blacks is a the back of my mind, but now my focus is on the Chiefs, getting that right and playing well for my Super Rugby franchise. If and when playing for the All Blacks at the World Cup does come along, we'll sort of worry about all that stuff then."
Retallick has played 75 tests and been a world player of the year but there appears to be no dimming of his talents.
He's mindful of the turnover of talent New Zealand will experience with the usual World Cup drain already under way as top players sort out their long-term futures ahead of the tournament.
All Blacks captain Kieran Read has already confirmed he will join the Japanese scene after the World Cup and several All Blacks are joining him on the exodus of talent.
"Kieran has been around for a long time and is certainly both a great player and leader, so there is definitely going to be a void there. But what New Zealand rugby prides itself on is that when someone steps away, it's an opportunity for someone else to fill the void and stamp their mark on the black jersey. I'm sure that there are some young boys already wanting to step into the jersey when Kieran and a few others opt to go post-World Cup," Retallick told Sport24.
Retallick, who helped the All Blacks win the 2015 World Cup in England, describes this year's tournament in japan as "wide open".
"Playing at a global tournament is a different ball game because there is a lot more pressure and the style of rugby is not the same to what we are used to in the Rugby Championship," he said.
"I think there will be a lot of teams going to Japan with high hopes to come out on top. Any team that wins the Six Nations has to be playing good rugby. I watched Wales beat Ireland and was hugely impressed with the Welsh team. They are working hard and have a great kicking game. You can't say that Wales aren't going to be in it from September, along with England and Ireland.
"I think it's going to be a very competitive World Cup event and we know what Australia, Argentina and South Africa can produce having played them in the Rugby Championship. And, once we play the other southern hemisphere teams in the Rugby Championship this year, we can see where everyone is at after what the Six Nations teams delivered."
Retallick felt the All Blacks and New Zealand rugby in general were making progress with the rush defence opposition teams employed against them last year with a good deal of success.
The Springboks beat the All Blacks 36-34 in Wellington and almost repeated that in Pretoria, losing 32-30 after leading 30-13 heading into the final quarter.
"The Springboks beat the All Blacks in Wellington during last year's Rugby Championship by turning out with huge physicality, drive and their line-speed on defence. They put us under a lot of pressure and we weren't finding the holes," Retallick said.
"It looks like their Super Rugby franchises have taken a bit of that from the Springbok side. However, I think it [line-speed on defence] is something New Zealand has caught up with, and many of our teams across the board are now defending like that.
"It's something we have been dealing with during the back end of Super Rugby and then especially at the start of this year, with the way the Crusaders and Hurricanes defend. We are now a little bit more adapted to that tactic and are keen to put our attacking game on the park."