Brodie Retallick won't play against Ireland because of concussion, resulting in a double change at lock for next week's Test in Chicago.

Team management confirmed Retallick would join Sam Whitelock in missing the first Test of their four-leg northern hemisphere tour following the head knock suffered during Saturday's 37-10 win over Australia.

Whitelock is sidelined for 3-6 weeks with a high ankle sprain, meaning the All Blacks will lose 139 caps worth of experience against the Irish.

Luke Romano and Patrick Tuipulotu, who have both made sporadic appearances this year, are expected to start.

Uncapped Cantabrian Scott Barrett, who was named as injury cover for the tour, will be on the reserves bench if the selectors want specialist lock backup in Chicago.

The injuries mean athletic Wellington lock/flanker Vaea Fifita will travel with the 36-man squad on Friday to act as cover for the Chicago Test at least.

Fifita and Barrett both enjoyed excellent Super Rugby campaigns for the champion Hurricanes and the Crusaders respectively.

The injuries are significant for the All Blacks, with World Cup-winning pair Retallick and Whitelock having played to a high level throughout their unbeaten season to date.

Romano, 30, has added four caps to his 26-Test career this year, enjoying one start in the season-opener against Wales in Auckland in June.

Tuipulotu, 23, has played eight of his 10 Tests off the bench. His three Tests this year featured a start against Argentina in Buenos Aires.