After his international farewell this year and some back surgery, he picked up a deal with the Trinbago Knight Riders and had a couple of practice games for the Heat before he walked out to open their batting in game one this week in Adelaide.
McCullum was miked up during his pyrotechnic two-runs-a-ball 42 and he spoke about his see-it, hit-it philosophy, which is so dangerous in this form of the game. Opposing Strikers skipper Brad Hogg confirmed the unconventional danger McCullum presented and said it depended on whether it was a day for Baz or the bowler.
Remember those ramp shots for six, the front foot pulls, reverse sweeps or the three-step glide then pound over long off that McCullum used when he was in his pomp. He's 35 now and probably not as sharp between wickets as he was, but he is still honed for cricket between the ears, with his reactions and his powerful wrists.
It was a juicy reminder of what New Zealand has lost and an enticing reminder that McCullum's former team will unfurl the one-day colours against Bangladesh on Boxing Day. It's Kane's crew now, a side who were slapped around in Sydney, Canberra and Melbourne this month and need to restore their reputation.
There have been some amendments since those Chappell-Hadlee defeats.
Experienced batsman Neil Broom has been picked to help a lineup devoid of the injured Ross Taylor and pinch-hitting gloveman Luke Ronchi brings his skills to try to help enliven contributions.
Test keeper BJ Watling, struggling middle-order batsman Henry Nicholls and all-rounder Todd Astle are the initial casualties and there should have been more. However, the list of potential replacements is limited.
If the recasting does not work, it will be a tough summer. However if New Zealand can ingest some of that McCullum verve and gather a bit of his dash and spirit against Bangladesh, then they can move in to the next campaigns against Australia, then South Africa, in much better shape.