Adelaide defender Wayne Milera could miss the entire AFL season after suffering a serious knee injury in the Crows' practice match against Port Adelaide.
Milera, who played just two games last season because of a stress fracture to his foot, ruptured his patella tendon in the second quarter of Saturday's 52-point loss to the Power.
The 23-year-old will undergo surgery in the next 24 hours, and he faces an uphill battle to play again in 2021.
Port duo Charlie Dixon and Xavier Duursma booted three goals apiece in the 18.17 (125) to 11.7 (73) win.
Power's Todd Marshall suffered a cheek injury in the second quarter and sat out the rest of the match.
But it was Milera's injury that was the talking point of the day, with the luckless defender now set for another frustrating stint on the sidelines.
The No.11 pick from the 2015 national draft had set himself for a big season after recovering from last year's serious foot injury, with his aim to secure a spot in Adelaide's midfield.