Port Adelaide forward Mitch Georgiades requires a knee reconstruction and will miss the rest of the season.
Georgiades, who hasn't featured in AFL ranks since round two, tore the anterior cruciate liagement in his right knee in the state league last weekend.
"He'll see a surgeon in coming days to organise reconstructive surgery and then spend several months rehabilitating," Port's medical chief Tim O'Leary.
"We know an ACL is a tough injury for any footballer but Mitch is a really positive person who attacks training hard and we know he'll attack his rehab in the same way."
The Perth-born 22-year-old falls off-contract at season's end and is a rumoured trade target of West Coast.
Power halfback Kane Farrell will miss about three games, including Friday night's early-season litmus test against ladder leaders St Kilda, after suffering a broken cheekbone in Saturday's win over West Coast.
Spearhead Charlie Dixon's knee injury will be put to a test later in the week to determine his availability.
And captain and fullback Tom Jonas has accepted a one-game suspension for rough conduct after his bump on West Coast's Jai Culley.
Port downed the Eagles by 40 points, their fourth win of the season putting them in sixth position on the ladder.
But assistant coach Nathan Bassett said a true examination loomed with a Friday night date against St Kilda, the only club currently with five wins from six starts.
"They have certainly performed very strongly," Bassett said.
"Defensively, they're very well organised and they're difficult to score against."