The 24-year-old will fight Fiji's Sachin Mudaliar over six three-minute rounds on the Paul Gallen-Darcy Lussick undercard in Sydney on Wednesday night.

Mudaliar (9-1) is experienced but largely unknown, with a 2019 split decision defeat of Ben Dencio to claim the vacant ANBF super featherweight title his only career fight outside of Fiji.

Happy to admit he's seen little of his first-up rival, lightweight Garside will lean on years of amateur know-how to announce himself as a professional in style.

"I haven't seen too much footage but my amateur career has set me up for that, not knowing who we fight until the day before," the 2018 Commonwealth Games champion said.

"I'm excited to get in, adapt and I don't want it to go six rounds, I want that $20,000 (bonus for the best knock out on the card).

"I've been an amateur sportsman, I was broke for 15 years, we need that money."

Garside has a ready-made following after the ballet-dancing, fingernail painting plumber from Victoria made an emotional passage to the final four in Tokyo.

He left nothing in the ring and offered plenty out of it, encouraging others to break stereotypes and be themselves as he became Australia's first Olympic boxing medallist since Grahame Cheney won silver in Seoul in 1988.

A long apprenticeship now under his belt, Garside has lured Australian boxing legend Johnny Lewis out of retirement, hoping he can become the seventh fighter Lewis has guided to a world title.

"We met and within five minutes I knew there was something special about him," Lewis, who trained Jeff Fenech and Kostya Tszyu, said in October.

"I honestly do believe in him. He's made for it, he's got great height and a beautiful reach."

Garside will paint his fingernails in green and gold for his debut professional fight and says his flowing mullet will be cut off after the bout.

But it's not as if he's been distracted from the task at hand.

"Every fighter dreams of waking up in fight week and I've jumped out of bed, feel like a bull at the gate and I'm just waiting for it to open," he said.

"I love the pressure ... this is all I've ever known since I was nine.

"My weight's good, I'm feeling good mentally, physically and emotionally and the journey to the top starts on Wednesday."

MAIN CARD (from 7pm Wednesday AEDT)

Paul Gallen v Darcy Lussick (heavyweight) (3x 2-minute rounds)

Harry Garside v Sachin Mudaliar (lightweight) (6x3-minute rounds)

Joey Leilua v Chris Heighington (heavyweight) (4x 2-minute rounds)

Freddy Lussick v Taylan May (cruiserweight) (4x2 minute rounds)

Sam Goodman v Richie Mepranum (bantamweight) (10x3 minutes rounds)

Justin Hodges v Nathan Ross (heavyweight) (4x 2-minute rounds)

Alex 'Godly Strong' Simon vs Tavita Vaoga (heavyweight) (4x3-minute rounds)

Enja Priest vs Ella Boot (catchweight) (4x2-minute rounds)

From 6pm AEDT

Linn Sandstrom v Natalie Gonzalez Hills (super flyweight) (6x2-minute rounds)

Australian Associated Press