Greater Western Sydney coach Leon Cameron will be forced to re-examine the Giants' game style after running defender Zac Williams ruptured his Achilles tendon at training on Friday.
The injury leaves the Giants without their two best rebounding half-backs from the previous two seasons after the club lost Nathan Wilson during the trade period after he joined Fremantle to be closer to family.
Williams and Wilson combined for 90 games in the past two years as the Giants made consecutive preliminary finals.
The team generated many scoring opportunities because of the pair's ability to slingshot the ball from defence.
The club may be forced to push former Tiger Brett Deledio back into Williams' role as he looks to contribute more after injury restricted him to just seven games in his first year at his second club.
Williams, 23, is expected to meet with surgeons on Monday to determine his process to recovery but a ruptured Achilles could put him out of action for the bulk of 2018.
Giants head of fitness David Joyce told the club's website the injury was frustrating for Williams.
"Zac will meet with a specialist early next week to determine the extent of the injury which will allow us to then map out the best possible management pathway," Joyce said.
The Giants already have emerging defenders Adam Kennedy and Matt Buntine returning from knee reconstructions and Toby Greene suffered a broken toe while on holidays in the off-season.
The club conducted a review last season into their conditioning after an unfortunate run with injuries virtually derailed their year. The review found many of the injuries were simply due to bad luck.