AARON Nietschke will miss the 2019 AFL season after scans have confirmed he has ruptured his right anterior cruciate ligament.

The 18-year-old suffered the injury during a training session at Casey Fields on Friday morning.

General Manager of Football Operations Josh Mahoney said it was a tough blow to lose youngster Nietschke for the remainder of the year.

"Unfortunately, scans have confirmed that Aaron has ruptured his ACL,” Mahoney told Melbourne Media.

"He will meet with the surgeon today, with the most likely option being that he will miss the year.

“This is obviously a tough time for Aaron – as a club we will ensure we put the best support around him during the rehab process, like we do for all our players.”

Recruited from Central Districts in Adelaide, Nietschke was selected by the Demons with pick No.53 in the 2018 National Draft, after he impressed with his ability to run all day and slot into multiple positions.