North Melbourne recruit Griffin Logue will be sidelined for up to 12 months after rupturing his ACL in the Kangaroos' defeat to Geelong.
The defender was subbed out of Sunday's loss at GMHBA Stadium during the first quarter, with North's stand-in coach Brett Ratten fearing the injury was serious.
Scans on Monday confirmed Logue had suffered the dreaded knee injury and would miss the remainder of the season and beyond.
"Despite knowing his injury was serious, Griff continued to support his teammates throughout the game," North football boss Todd Viney said.
"The way he went about it is a testament to the professional he is.
"Everyone at the club will be there to support him as he begins the first steps of his rehab."
Logue has featured in 15 games for North this season after landing at Arden St from Fremantle in last year's trade period.
The Kangaroos are on a 14-game losing streak ahead of this Sunday's match against Hawthorn at Marvel Stadium.
Their dream 2-0 start to the season ended at the hands of the Hawks in round three with a 19-point loss in Launceston.
Coach Alastair Clarkson will continue easing his way back into work after stepping away from North in May, but will leave it until after the match against his former club to take the reins back from Ratten.