The newly installed skipper said the inevitable result of the intense criticism the players experienced in the past couple of years was to become introspective.
"We've lost that romantic notion of building a team," he said. "We've focused so much on individual improvement we've almost lost sight of the importance of team."
Last week was a brutal one for the sport. New Zealand Cricket, no strangers to tumult, took things to a new level with the Ross Taylor captaincy fiasco.
McCullum, the "beneficiary" of Taylor's demotion as short-form captain and resignation as test captain, knows they have ground to make up.
"We have to try to build a good culture after everything that has happened. We're going to have to look after some blokes in order to get there."
Two of them are Taylor, who has decided not to travel to South Africa as he attempts to clear his mind, and Jesse Ryder.
New Zealand does not have enough depth in its talent pool to have the country's two best batsmen in a prolonged state of disillusionment and national exile.
Reparations will have to wait, however, for McCullum as the focus has to switch to those he has alongside him as he takes on South Africa in three T20 internationals, two tests and three ODIs. New Zealand leave tomorrow to begin their build-up.
McCullum said he would be "racking my brains" over the next 48 hours as he gets to grip with the enormity of the task.
"It's going to be as hard as anything we've ever had to face," he said about taking on the best side in the world on their home turf.
"First of all we have to acknowledge their strength and then look at areas we can try to exploit."
The 167-run win at Colombo has at least provided a blueprint for how they will look to approach test cricket. That victory was founded upon two players in the top order - Taylor and Kane Williamson - scoring big runs and batting time. That kept Sri Lanka's big batting guns in the field a long time and allowed New Zealand to attack them late in the day.
It is the burgeoning seam bowling attack that gives McCullum the most hope of heading up the rankings with Tim Southee, Trent Boult, Doug Bracewell, Chris Martin, Neil Wagner, Mark Gillespie, Mitchell McClenaghan and Adam Milne able to move the ball upwards of 135km/h.
"Injuries will mean they're not all available at the same time, but these are guys who can ask a lot of questions of batsmen and can be used as attacking weapons."
Attack is a word often associated with McCullum, sometimes to his detriment.
In terms of his captaincy philosophy, he says it is fair to assume he will take chances at times. With experience, he says, he will learn what gambles are worth taking, and which to discard.
South Africa tour
Dec 22: 1st T20, Durban
Dec 24: 2nd T20, East London
Dec 27: 3rd T20, Port Elizabeth
Jan 2-6: 1st test, Cape Town
Jan 11-15: 2nd test, Port Elizabeth
Jan 19: 1st ODI, Paarl
Jan 23: 2nd ODI, Kimberley
Jan 26: 3rd ODI, Potchefstroom
Dates NZT
- Dylan Cleaver of the New Zealand Herald
