Bulldogs medical services manager Chris Bell revealed scans had confirmed the worst for the 24-year-old.
“Scans have today confirmed Toby has sustained an ACL injury,” Bell said.
“Toby will return to Melbourne today and have a surgical opinion over the next couple of days to determine the best course of action for him.”
The premiership Bulldog had shown great improvement in 2020, namely in his best-on-ground perforce against the Eagles in round 16.
Bulldogs coach Luke Beveridge lauded McLean’s importance to the team.
“He’s versatile, he’s been important with some of the roles he’s played this year,” Beveridge said post-game.
“He’s a resilient character, Toby. He’s been through a lot in his life, not just his footy career.
“Tobes will be okay. We’ll get him through, we’ll support him… He’s still got many years ahead of him, and hopefully many productive years as a Western Bulldogs player.”