"It's going to be massive, 40,000 people [at the Sydney Cricket Ground]," Munro said pre-match. He was dismissed for one off seven balls, bamboozled by a series of leg spinner Fawad Ahmed's variations.
"It [the BBL] is one of the biggest competitions in the world and to get the recognition to come and play is awesome."
He has a second match to show what he can do as the Sixers push for a finals berth. Munro says he sought out McCullum, the Brisbane Heat captain, for advice about the tournament.
"[He] said come out and play your way. If you do come off you can take the game away.
"A lot of people back home said you've got two shots, go and make it work, so no pressure. You play around the world and get to know different players and that's how these opportunities come about."
Munro has represented New Zealand in all formats - his only test came against South Africa at Port Elizabeth in 2013 - but his global experience in T20 leagues prompted the Sixers to recruit him after they missed out on the injured Martin Guptill.
"He was signed before me and then his hamstring injury came about," Munro said.
"There was some shuffling with New Zealand Cricket, trying to get away from playing our domestic competition, but obviously I'm pleased they jumped on board.
"I still want to play test cricket, but at the moment the white ball is taking care of itself in both those formats."
McCullum, speaking to Newstalk ZB's Tony Veitch from a Gold Coast poolside with his family, weighed into the debate on how test cricket sustains itself in the wake of T20's burgeoning popularity.
"We can put our heads in the sand and say everyone should want to represent their country, and I think first and foremost people do, but there's an opportunity cost as well.
"You look at a guy like Colin. T20 teams around the world look at him and see him as an excitement machine, yet he can be - without being disrespectful - out at Eden Park No.2, on an overcast day playing a four-day game where he doesn't really enjoy it and he's playing for $1000. [Alternatively] he can go and play in front of a full house at the SCG or the MCG and get $25,000 a game and be loved and wanted the whole time.
"You've got to do the maths. There will certainly be guys in New Zealand who will be thinking the T20 circuit is for them. The danger is that you have to earn the right as well... and that's where New Zealand Cricket has been excellent for us, they've understood it and given us opportunities."
