Collingwood defender Tyson Goldsack will miss the 2018 season after scans confirmed the 30-year-old ruptured his anterior cruciate ligament against the Western Bulldogs on Saturday.
Goldsack suffered the injury late in his side's win, and reportedly ran off the ground unassisted, before complaining to the bench of soreness in his knee.
The defender went in for scans which confirmed the injury, although Goldsack and the Pies were surprised the injury was that serious according to The Age, given the manner in which he left the field of play.
The Pies will likely send Goldsack in for season-ending surgery soon.
Goldsack signed a one-year deal at the end of last season, but is hopeful of continuing on in 2019.