GWS have confirmed Phil Davis' season is over because of a hamstring injury which also threatens to end the defensive stalwart's AFL career.
Scans have revealed a ruptured tendon after Davis suffered a right hamstring injury in Saturday night's 55-point loss to Port Adelaide.
The latest injury is on the opposite side to the hamstring injury that sidelined the 31-year-old former Giants captain during the first half of the season.
Davis and the club will consult with specialists this week to determine the next steps.
"We're gutted for Phil," GWS head of medical services James Rahme said.
"He's diligent in the way he goes about everything, including his rehab, and it's disappointing for him given all the work he put in to get back from his last hamstring injury.
"We're in the process of seeking some specialist opinions this week for a more detailed prognosis, and to determine what the rehabilitation plan looks like for him."
Davis turns 32 next month and comes off-contract at the end of the season.
Giants interim coach Mark McVeigh was reluctant to discuss Davis' future in depth but believes the 192-gamer has more to offer.
"Phil is someone who's very resilient and can manage and rehab injuries really well - and he has had some bad ones over the years," McVeigh said post-match on Saturday night.
"It's probably not one for me to discuss the future in that regard so I would like to keep that very respectful.
"But from my point of view, I have valued who he has been for the club for a long period of time and the appropriate people will have those conversations, however that looks.
"I am not even sure of his contract status to be honest. It's a hard one."
GWS will also be without Adam Kennedy for Saturday's clash with Brisbane in Canberra after the defender suffered concussion during the Port Adelaide loss.
Connor Idun will be available after missing one match while in health and safety protocols.
