Penrith playmaker James Maloney has been ruled out of Saturday's clash with the nib Newcastle Knights at Panthers Stadium.
The NSW Origin half picked up an injury against the Gold Coast last week.
Scans on Monday revealed the full extent of the knee injury which is a grade two medial ligament injury.
As a result, Maloney will miss Saturday's game and spend the coming weeks on the sidelines.
Maloney's replacement for Round 23 will be named when Panthers coach Cameron Ciraldo selects his squad on Tuesday afternoon.