Jackson Ford's ankle injury has ruled him out this weekend, but the New Zealand Warriors have not ended his season.
Ford could return for a potential Preliminary Final, or the Grand Final if necessary, although the club has provided no official timeframe.
The prop had only recently resumed playing after a mid-season injury ended the second half of his campaign.
He lasted 24 minutes against the Dolphins in last weekend's Qualifying Final defeat before an awkward tackle caused the latest setback.
James Fisher-Harris and Mitch Barnett remain the starting forwards for Andrew Webster's team, with Demitric Vaimauga and Tanner Stowers-Smith expected to provide middle-cover support.
The Warriors face a Knights side buoyed by an upset victory over South Sydney at Allianz Stadium last Friday.
Roger Tuivasa-Sheck and Tanah Boyd will miss the rest of the season with ACL injuries.
Rocco Berry and Luke Metcalf, however, remain possible finals returnees after hamstring problems. Berry may struggle to reclaim a place, while Metcalf could start or come from the bench around the Preliminary Final stage.