Brabham has been given a late call up to partner Ross Poulakis in his Customer Sports and Restorations-run Mercedes GT4 car.
The pair will team up for the two one-hour races, their sights firmly set on topping to the thin GT4 field for the opening round of the GTWCA season.
For Brabham the drive is significant in that it will mark his debut race on Aussie soil.
His previous experience has come mostly in the UK where he raced Carrera Cup and Formula Ford.
Brabham has been based in Australia, working as a driver coach, since 2020.
“It’s been a late call up to this, but I’m ecstatic and delighted to get the opportunity,” he said.
“It’s my first proper race in Australia, which is strange because I’ve been living in Australia for almost two years, but with COVID and other things, I haven’t been in the position to race. Now the stars have aligned and this is pretty awesome.
“I’ve been coaching the guys who race this car, so I have some knowledge of the car, and I’ve done plenty of laps around Phillip Island too. It’s probably the circuit that I’ve driven on the most here in Australia.
“I have a reasonable base of knowledge to get started, so I should be fine and I’m looking forward to working with Ross and the team.”
There are more than 20 cars on the grid for the GTWCA opener, with some big names in the top GT3 entires.
That's particularly true for the Audi armada, which includes pairings Chaz Mostert and Liam Talbot, David Reynolds and Tony Bates, and Chris Mies and Yasser Shahin.
Shane van Gisbergen will partner Prince Jefri Ibrahim in the Triple Eight Mercedes while Tony D'Alberto will share a Lamborghini with Adrian Dietz.
The GT World Challenge Australia action from Phillip Island will be shown live and free on Motorsport.tv (local restrictions apply).