Galea has a hamstring strain and as a precaution, will miss the game. His replacement in the number 23 jersey will be Bronson Harrison, who has overcome a hamstring injury himself to be fit for the game.
The Roosters have also lost Josh Lewis and Adam Schubert for the game. They have been replaced by Craig Wing and Chris Flannery.
Gates open at 3.45pm. Jersey Flegg starts at 4pm, Premier League at 5.30pm, and first grade at 7.30pm.