Opening batsman Tom Latham was probably most under pressure after scores of 10, 8 and 6 in the current Test series and 7, 0, 0, 2 and 0 in preceding limited-overs global matches against South Africa.
So far against South Africa, the T20 - albeit a one-off - was a walkover for the visitors, the one-day series was an oscillating affair, but two very bad batting displays in Wellington and Auckland cost New Zealand, and now they are 1-0 down in the Tests after collapsing for 171.
"To lose within three days is unacceptable and the group is hurting and disappointed". "We need to get him back to making those good decisions and everything else will flow from there".
The Blackcaps struggled against South Africa's spin bowlers on a wicket that was not turning much, and McMillan admits the entire team should have been better prepared for the match.
Larsen said if there were other opening batting candidates who were "shooting the lights out and putting in front of the selectors really compelling reasons to pick them then we would have had that discussion (about dropping Latham).so I guess that's a challenge from me to domestic batsmen - 'get out there and put the numbers up". Obviously the one-day games it did. "Even that last-wicket partnership between Philander and Morkel which pushed the lead from 30 to 80 was quite a telling point - those two guys stood up and that's what we need our guys to do".
New Zealand will still be without their most experienced batsman however with Ross Taylor still sidelined with a calf injury.
Seamer Trent Boult is expected to be fit enough to take his place in the XI after missing the second Test in Wellington which will once again leave the Black Caps with some selection puzzlers. We haven't had too many openers who have done that. "I think he's the best No 3 in the world", McMillan said. "He's working hard. Internally I'm sure he's feeling it, anyone would".
Latham isn't going anywhere - McMillan reinforced the best players in the country are in the test squad - and expect him to be encouraged, if perhaps with fingers discreetly crossed behind backs, to find a ladder out of the hole he's in at Seddon Park.
They did compete in Dunedin, but a lot can change in a few days.