MELBOURNE, AUSTRALIA - MARCH 09: Marty Hore of the Demons handballs during the 2019 JLT Community Series AFL match between the Melbourne Demons and the Brisbane Lions at Casey Fields on March 09, 2019 in Melbourne, Australia. (Photo by Darrian Traynor/Getty Images)

Melbourne defender Marty Hore has been ruled out for the entire 2021 season after rupturing his ACL at training on Friday.

Hore was assisted from Casey Fields after being tackled at training, with the 24-year-old eventually undergoing further assessment to diagnose the extent of the knee injury.

"Unfortunately, the scans have confirmed that Marty has ruptured his ACL and will miss an extended period of time," Demons head of football performance Alan Richardson told Melbourne Media.

“This is devastating news for Marty and the club, as he was preparing for the season ahead.

“Marty is a very impressive and resilient person, and we will fully support him through his rehab.

"He'll meet with the surgeon next week to discuss the appropriate treatment required to repair the ACL."

Hore made his debut with the Demons in 2019, going on to play 14 games for the club before toe and quad injuries ruled him out of playing the entire 2020 season.