The AFL season is over for Richmond's Steven Morris, with scans confirming the combative defender ruptured the anterior cruciate ligament in his right knee early in Friday night's 70-point loss to North Melbourne.
Morris, 27, will undergo surgery in the coming weeks.
"The injury is disappointing for Steve, he's a tough competitor and has been playing great football this season," said Richmond's general manager of football Dan Richardson.
"It's never easy to see a player go down with a long-term injury, but Steve is a resilient person and we'll support him throughout the rehab process."
Three other Tigers are in doubt for Sunday's clash against Gold Coast due to injuries suffered on Friday night in Hobart.
Ruck-forward Ben Griffiths has a lateral ligament sprain in his right ankle, while Dylan Grimes felt hamstring soreness during the warm-up and was a late withdrawal.
Defender Nick Vlastuin was concussed during the second quarter against the Kangaroos.