GWS insist Jon Patton will come back bigger and better next AFL season, with the key forward facing a long road back from a third knee reconstruction.
Patton's worst fears were confirmed on Friday morning, with scans revealing the the 25-year-old has ruptured the anterior cruciate ligament (ACL) in his left knee.
The former No.1 draft pick needed reconstructions in 2013 and 2014 after ACL injuries in his right knee.
Patton also required surgery to fix a patella tendon problem in his left knee before the 2012 season.
"We'll work out when he has surgery over the next couple of days and map out a plan," GWS football manager Wayne Campbell told radio station SEN.
"If he comes back in 10 months, he's due in the first month of next season.
"So it's not like next year is a write-off.
"A bit of light at the end of the tunnel and I think he's starting to see that already."
Dan Menzel headlines the list of players to have successfully returned after a series of knee reconstructions, while Clay Smith lifted the 2016 premiership after undergoing three right knee reconstructions in the previous three years.
Campbell admitted Patton was "almost inconsolable" after the innocuous incident at training on Thursday, but has now come to grips with the challenge ahead.
"He's shown the resilience to fight back from serious injuries in the past and we're confident this will once again be the case," he said.
"For any player to have one knee injury is a setback. To have two is greater than that, but to have three ... in footy terms, it's a real tragedy.
"He has the full support of everyone at the Giants, and I'm sure the wider football community, as he faces this next challenge."
Patton's setback is a major blow to the seventh-placed Giants' AFL finals hopes.
GWS will be without their top four goal-kickers from last season during Sunday's match against the Eagles in Perth, with Patton, Toby Greene (foot injury), Jeremy Cameron (suspended) and Steve Johnson (retired) all unavailable.
"We feel like we've got the side to not only beat West Coast this weekend, but win enough games to put us in a really good spot for finals," Campbell said.
GWS have endured a horror run on the injury front this year, although Greene and Brett Deledio (calf) are both in line to return against Richmond next week.
A foundation GWS player, Patton has played 89 senior games.