He also offered a positive leave to any references about this being his farewell tour, preferring to transfer the focus back to the team's holistic ambitions.
McCullum knew where his off stump was, as he has done at most press conferences in his three-year captaincy tenure.
However, it seems unlikely he will apply that same defence tomorrow, if past actions are a gauge.
The last time Australia played at Eden Park was the World Cup pool match when McCullum top-scored for New Zealand with 50 off 24 balls, giving them the impetus to carry on to a one-wicket win and, eventually, their first final.
Crowds well into the 30,000 bracket are expected for this match in which New Zealand have called up leg spinner Ish Sodhi in the hope of benefitting from turn on the same drop-in pitch used against Pakistan on Sunday.
"The wicket was slow the other day," McCullum said. "If we think it will hold up we will look to include him."
The move was also sparked by Pakistan captain Azhar Ali spinning a ball past Kane Williamson to have him stumped for 84.
"Not too many people get past Kane," McCullum said. "The wicket had more turn than expected. The beauty of playing at home means we can bring guys in at short notice."
McCullum's own fitness had him feeling "stiff and sore" after his first international of the year.
"The outfield was incredibly heavy, which a lot of guys commented on, especially coming in with a sore back."
Australian have opted against playing specialist leg spinner Adam Zampa in the opening match.
Captain Steve Smith said he expected the ball to swing in light of how movement influenced the World Cup pool match.
He urged his players to "back your defence because you can make runs at the back end" in matches in New Zealand.