Plague Stone will be Godolphin's first runner of the winter carnival when he contests Saturday's Listed Mick Dittman Plate (1100m).
A gelding by Lonhro out of stakes-placed Giggleswick, Plague Stone raced in top company as a two-year-old finishing second in a Blue Diamond Prelude when beaten less than a length by top sprinter Written By.
Plague Stone has had two trials to prepare for the winter, winning the latest at Rosehill two weeks ago.
Cassidy is cementing himself as a rider for Godolphin in Brisbane when they don't use a Sydney jockey.
He has two wins, including the Listed Nudgee Quality on Manicure, from three rides for Godolphin this season.
“It is always an honour to ride for Godolphin. You know whenever you get on a Godolphin horse you have a real chance,” Cassidy said.
Godolphin Australian manager Vin Cox confirmed the organisation expected to have a strong hand in Brisbane this winter.
It could be a big day for Cassidy who will also ride the favourite Order Again for Brian Smith in the Listed Tails Stakes .