Melbourne have confirmed that draftee Aaron Nietschke ruptured his ACL at training on Friday to prematurely end the youngster's 2019 season.
The South Australian product was taken with pick 53 in last year's draft and is set to see a surgeon on Monday.
Demons GM Josh Mahoney confirmed that the 18-year old would likely sit out this season.
"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.”
Nietschke claimed the SANFL U/18 best and fairest last season after averaging 32 disposals per contest for Central Districts.
