The All Blacks are going to extra lengths to uncover their next Test hooker.

A succession-planning programme has been launched that will see some of New Zealand’s best young hookers train with the All Blacks ahead of their three remaining home Tests this year.

Otago and Highlanders hooker Liam Coltman, 23, will train with the All Blacks this week ahead of the Saturday’s second Bledisloe Cup Test against Australia in Wellington.

Two others will be invited into the camp ahead of Rugby Championship Tests against Argentina in Hamilton on September 7 and South Africa in Auckland a week later.

Contenders for those spots include Chiefs hooker Rhys Marshall, Crusaders pair Ben Funnell and Codie Taylor and Highlanders front-rower Brayden Mitchell.

A New Zealand Rugby Union release said the “apprentice-like” programme was designed to build depth in the position.

“The aim is to have the young hookers train with the squad, spend some time in the All Blacks environment and learn from the All Blacks experienced hooking duo of Keven Mealamu and Andrew Hore.”

Hore and Mealamu, both 34, have played 182 Tests between them but face a challenge to hold onto their All Blacks jerseys ahead of 2015 World Cup.

Hore started the 47-29 win over the Wallabies on Saturday while Mealamu came off the bench.

The third hooker in the All Blacks’ squad for the Rugby Championship is Dane Coles, 26, who holds prime position to succeed the pair but wasn’t deemed fit for the Sydney Test.