Last year seven new players - Frank Halai, TJ Perenara, Luke Whitelock, Bird, Joe Moody, Ardie Savea and Jeff To'omaga-Allen - were picked with Moody withdrawing because of a broken leg, while the year before Dane Coles and Tawera Kerr-Barlow were the fresh men.
Only Perenara, Bird and Moody from last year's intake are in the hunt again.
If Carter convinces the medics he is fit, he will provide cover in midfield and allow Colin Slade to make the trip as someone who is primarily a first receiver yet versatile enough across the rest of the backline and is a goal-kicker.
Carter's inclusion looms as bad news for his provincial teammate Ryan Crotty who would be squeezed out with Sonny Bill Williams returning to the mix.
Malakai Fekitoa is a certainty in midfield after his striking debut season while Williams will be back in the mix but his time on tour will be interrupted. His wife is due to give birth next month and Williams wants to be with her for that. Last year's special project Ardie Savea has undergone shoulder surgery and will not be seen until next year's Super 15 while Kerr-Barlow, Nonu, Luke Romano and Tony Woodcock are also on the injured roster.
Announcements that Halai, Francis Saili, Adam Thomson, Tim Nanai-Williams and Patrick Osborne will play for the Barbarians next month, confirms they will not make the All Blacks.
Room for experiments in a touring squad of 18 forwards and 15 backs is limited. The coaches and selectors will have sorted out 90 per cent of the squad they want for next year's World Cup with their final choices depending on who crests into form to make the final few vacancies.
They will want more competition at lock and hope Romano recovers to bring that edge to the competition next year.
The squeeze will continue at prop with Charlie Faumuina's ability to play both sides putting extra heat on Ben Franks to retain his place once Woodcock is repaired.
Possible tour squad
Backs: Israel Dagg, Ben Smith, Cory Jane, Julian Savea, Charles Piutau, Conrad Smith, Sonny Bill Williams, Malakai Fekitoa, Daniel Carter, Colin Slade, Beauden Barrett, Aaron Cruden, Aaron Smith, TJ Perenara, Augustine Pulu.
Forwards: Kieran Read, Jerome Kaino, Liam Messam, Steven Luatua, Richie McCaw, Sam Cane, Sam Whitelock, Brodie Retallick, Patrick Tuipulotu, Dominic Bird, Joe Moody, Wyatt Crockett, Owen Franks, Charlie Faumuina, Ben Franks, Keven Mealamu, Dane Coles, Nathan Harris.