St Kilda defender Nick Coffield could miss the entire 2022 AFL season after suffering a suspected ACL tear at training on Friday.
The 22-year-old will undergo scans after suffering the injury to his right knee during the early part of a match simulation session, with the club already bracing for the worst.
"Early assessments from our medical team suggest it's an ACL, but we'll need to wait for scans to confirm the injury," chief operating officer Simon Lethlean said.
"This is obviously a really disappointing blow for Nick who has been showing positive signs all pre-season.
"Whatever the outcome, we know that Nick will attack his rehab with complete professionalism and the club will be supporting him every step of the way."
Coffield, the No.8 pick from the 2017 national draft, has played 52 games since making his debut in 2018.
He was axed three times last season before finishing the year with an impressive 21-disposal display in the round 23 win over Fremantle.
Meanwhile, Carlton ruckman Tom De Koning is no certainty to be available for round one after having a minor surgical procedure to remove a blood clot in his shoulder.
De Koning has now returned to skills training and will be integrated into other aspects of the program over the coming weeks.
Carlton said they will monitor the 22-year-old's health over the next month before deciding on his availability for round one.
