England full-back Sam Tomkins is out for up to six weeks with a partial tear of the posterior cruciate ligament in his left knee.
The 26-year-old picked up the injury in New Zealand Warriors round three victory against Parramatta Eels.
Tomkins was an ever-present for the Warriors in the 2014 National Rugby League, scoring 13 tries.
"Sam will rehab the injury and should be available again in a few weeks," head coach Andrew McFadden said.
He joined Warriors following a successful Super League career with Wigan, where he ran in 144 tries in 151 matches from full-back.