Friday, 19 January 2018: Greater Western Sydney back Zac Williams will miss the start of the AFL season after suffering a ruptured achilles at training.

Greater Western Sydney defender Zac Williams will be be sidelined for an extended period of the AFL season due to a ruptured achilles.

Embed from Getty Images
The 23-year-old defender, having played 76 games in five seasons, suffered the injury on Friday at training.

The Giants' website reported Williams would see a specialist on Monday to get the injury assessed and decide if surgery was required.

"This is a really unfortunate injury for Zac who had been training really well throughout the pre-season so far," Giants head of athletic performance David Joyce said.

"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."

Losing Williams for any length of time would be a big blow for GWS, who traded away their other dashing half back Nathan Wilson to Fremantle after last season.

Williams played 23 games in 2017, spending time in both the midfield and forward line as well as in his traditional half-back role.

GWS were preliminary finalists in the past two seasons, but suffered several long-term injuries in 2017.