Hawthorn rookie Tim Mohr has ruptured his ACL while playing for the club's VFL team on the weekend.
The 30-year old was immediately taken to hospital after dislocating his knee early in the game, with scans revealing an injured ACL and PCL.
Hawks physical performance manager Luke Boyd confirmed the news on the club website.
“Unfortunately, he has had significant damage around that knee,” Boyd said.
“He is booked in for surgery today and at this stage he is going to miss a large chunk of football.
“We will keep you updated in the coming weeks on how he is going.”
Mohr has totalled 48 AFL games for GWS from 2012 to 2018 before crossing to Hawthorn this season via the rookie draft.