Richmond's dream injury run among their top AFL stars is over, with Alex Rance to have a right knee reconstruction.
Scans have confirmed Rance has ruptured an anterior cruciate ligament.
The five-time All Australian will consult a surgeon on Friday ahead of surgery in coming days, Richmond said in a statement.
Rance landed awkwardly in the third quarter of Thursday's season-opening win over Carlton and was in agony as he limped from the MCG.
The injury makes this season the first since 2014 in which the top four Tigers - Rance, captain Trent Cotchin, Dustin Martin and Jack Riewoldt - won't play at least 20 games across the season.
Rance played 18 games in 2014.
Coach Damien Hardwick said some teammates were in tears on Thursday night as the severity of Rance's injury became apparent.
But he pointed to West Coast, who lost ruckman Nic Naitanui to a knee reconstruction, Andrew Gaff to suspension and Brad Sheppard (hamstring) on the way to last year's premiership.
"Last year, West Coast - Naitanui goes down," Hardwick said post-match.
"These things can be overcome."
He nominated young defender Ryan Garthwaite, who played two senior games last season, as a teammate who could take Rance's place.
Hardwick did not hide his bitter disappointment at the bad news.
"Your heart sinks because you've been through a lot with this guy, been through a journey," he said.
"Then to have it taken away from you (in) round one, it is disappointing.
"We walk away with four points, but we certainly walk away disappointed - we've lost a warrior.
"It's not to say they don't feel pain - I have guys in tears, knowing they've possibly lost a comrade for 12 months."
