Adelaide's Wayne Milera suffered a serious knee injury during Saturday’s practice match against Port Adelaide.
Scans revealed that Milera has ruptured his patella tendon after he came off the ground in the second quarter.
The luckless Crow will undergo surgery and could miss the entire 2021 season after playing just two games last year due to a stress fracture in his foot.
The Power beat the Crows by 52 points in the pre-season game at Alberton.
GWS’ injury woes have continued with recruit Jesse Hogan in doubt for the club’s Round 1 match against St Kilda.
AFL Media reports that Hogan injured his quad at training during the week and is expected to miss up to four weeks, ruling him out of all the Giants’ pre-season matches leading into the 2021 season.
The 26-year-old forward is seeking a fresh start after injuries restricted him to 19 games in two seasons with Fremantle.
Lachie Whitfield (bruised liver), Phil Davis (knee), Braydon Preuss (shoulder), Adam Kennedy (shoulder) and Brent Daniels (hamstring) have all had injury-interrupted pre-seasons for the Giants.
GWS face the Saints at Giants Stadium on March 21.