"They tried to put my nose back in a couple of times in the dressing room, although it still has a bend in it to this day.
"One thing I do remember is Wendell Sailor (who was running drinks for the Heat) going on in the rooms about how tough I was."
McCullum is an integral part of the Heat's plans to soar up the ladder from their sixth placing last season and he is one of the most important signings in their history.
A big attraction for McCullum to sign a two-year Heat deal was the chance to link with his former teammates Daniel Vettori (Heat coach) and Shane Bond (Heat bowling coach).
McCullum's wife Ellissa hails from Lismore, in northern New South Wales, and the batsman and father-of-three is looking forward to spending some time with his in-laws while in Australia.
With his tattoos and exhilarating shot-making, McCullum should be an entertaining smash-hit in Heat colours.
He will play in a far more evolved competition than in the first season when Heat staffers had to race down to Bunnings to buy teal paint and brushes to correctly colour his pads.
The pads required several coats of paint and were left to dry in the middle of the Sydney Cricket Ground on the day of the first Big Bash League game between the Heat and the Sydney Sixers five years ago.
"The Big Bash has become quite a big product, to the point where it is probably slightly dangerous for the future of international cricket," McCullum said.
"Big Bash games get massive crowds and huge promotion and the Aussie competition is hugely popular where I am from in New Zealand.
"Then sometimes you watch Test cricket, like the Australian Test in Hobart recently, and there are only a few thousand people in the grandstands.
"It is great to see how well the Big Bash has developed and I always thought if I was to play in it again that the Brisbane Heat would be my first point of call.
"Dan Vettori was very influential in getting me over here. He is a very loyal person and we spent a lot of time playing together for New Zealand."
McCullum is a flamboyant cricketer but has never forgotten his working-class background growing up in the tough streets of South Dunedin.
It was where his love of horses flourished as he and his mates preferred the local trotting track as a playground to some of the overgrown parks in the area.
Trotting trainers took the youngsters under their wing and gave them jobs cleaning stables, while racing officials had a soft spot for the kids and propped them up in stewards' towers.
It was an upbringing that McCullum remembered when he became the first New Zealander to score a Test triple century, against India in Wellington in 2014.
"Nah, no tear in the eye. I'm from South Dunedin," he said at the time.
McCullum shapes as exactly the right mix of style and substance the Heat are craving as they try to add another Big Bash trophy to the cabinet after winning the colourful competition in 2013.
