GWS star Jonathon Patton has been ruled out for Saturday's clash with Melbourne.
Patton, who has not missed a game since rounds two and three, will miss with hamstring tightness.
The 24-year-old has starred up forward this season, kicking 36 goals and ranking second at the club for contested marks.
The Giants are already without forwards Jeremy Cameron and Toby Greene, who are missing with a hamstring injury and suspension respectively.
Harrison Himmelberg comes into the 22, while Daniel Lloyd has been picked as an emergency.