Brisbane Lions could be without key defender Jack Payne for an extended period of time after an incident in the first quarter of the match against GWS.
The 25-year-old landed awkwardly in a marking contest late in the first term, crumpling to the ground after his left foot made contact with the turf on an angle.
After nearly a 10-minute delay, Payne was stretchered from the field of play, with substitute Kai Lohmann being activated into the game.
Payne will undergo scans on his left knee but the initial assessment from Lions doctors suggests a ruptured patella tendon.
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Brisbane will be hoping the injury is a similar to scenario to Sam Darcy earlier this season, with the Bulldogs forward's suspected ACL injury being a knee issue that resulted in only a two-month absence.
The injury is a huge blow to the Lions' hopes of defeating GWS, with Payne originally tasked with the role of shutting down Coleman Medallist Jesse Hogan.
Despite Payne's presence, Hogan kicked two goals in the first quarter and appeared to have his confidence back after kicking only two goals across his previous two matches.
Lions coach Chris Fagan has swung usual forward Eric Hipwood into defence to cover Payne's loss, with GWS' tall forward line already stretching Brisbane's back-line.