Ali Williams is an incumbent, but also has a knee injury which he aggravated in the second test against Ireland in June. Already struggling for form with the Blues this season, his best hope of a playing return following surgery is for Auckland in the second half of the ITM Cup. Whether the 31-year-old makes the end-of-year tour remains to be seen, although Hansen is a big supporter, mainly due to the experience the player's 75 tests provide.
Romano, who on Saturday against the Wallabies received a knock to a shoulder which troubled him for the Crusaders this season, offers a ball-running and defensive edge that neither Whitelock nor Retallick can quite match and Hansen will be eager to retain his services for the match against the physical Argentines.
And Hansen won't be the only one. With only three locks named in the squad, Hansen has raised the prospect of Kieran Read being press-ganged into the second row, something which the free-running No8 won't be overjoyed about.
The match in Wellington will be a significant one for centre Smith, if he does recover from his detached retina as Hansen believes he will. His quiet organising will be important in order to get the best out of Ma'a Nonu, returning to second-five following Sonny Bill Williams' exit. Nonu hasn't looked his best in his first two tests of the year, but is likely to be more comfortable at second-five alongside a player who so clearly complements him, rather than Williams, who is a similar type of player.
Loosehead prop Woodcock is on track to return from a rib cartilage injury, according to Hansen, who will be hoping for similar news on Romano.
With obvious depth in every other position - the All Blacks now have an embarrassment of riches at halfback and first-five following a few lean years - lock is the one position of comparative vulnerability, although how Robbie Deans would love to have such trifling concerns.