Penrith centre Jamal Idris is out for the season after tearing his ACL on Saturday night against Manly.
Idris injured his right knee in the 55th minute of his side's 22-12 victory over the Sea Eagles at Pepper Stadium when he slid underneath a Steve Matai tackle.
It is a big blow to the Panthers who were already struggling on the injury front with Peter Wallace expected to undergo surgery and Elijah Taylor also expected to be out for an extended amount of time.
Five-eighth Jamie Soward continutes to recover from lower back surgery and is not expected back for another week.