A hamstring tendon injury will keep GWS star Zac Williams on the sidelines for a month, robbing the AFL side of one of their most influential players.

The Giants hope Phil Davis, who also suffered a hamstring injury in their gutsy two-point win over Collingwood last week, will be fit to tackle Hawthorn on Sunday night.

GWS had been optimistic that Williams, whose rebounding run helped rattle Collingwood and snap a two-game losing streak, might also be in the mix to face the Hawks at Giants Stadium.

But scans have confirmed a fresh setback for the 25-year-old, who returned from an Achilles injury after the COVID-19 shutdown and is expected to be courted by multiple clubs this year as a restricted free agent.

The news is better for former co-captain Davis, who was also among the Giants’ best in round four prior to limping off in the third quarter.

“Phil just felt a little bit of tightness in his hamstring and we decided not to take any risks with him,” GWS head medico Cullan Ball said on Monday.

“He’s had a scan done. It came back really well for us.

“He’ll have a light day tomorrow then we’ll aim for him to train fully with the team on Thursday and if he can tick everything off there then we’d expect him to be available.”

Davis could find himself matching up on former teammate Jon Patton if the hulking Hawks forward is able to return from a foot injury this weekend.

Youngster Isaac Cumming, who played rounds one and two this season and would ordinarily headline the contenders to replace Williams, suffered a serious hamstring injury during last Friday’s curtain-raiser.

“It’s really disappointing,” Ball said.

“He’s torn that tendon in the upper part of his hamstring pretty badly, so we think he’ll miss somewhere between 10-12 weeks unfortunately.”