Penrith’s injury crisis has worsened with hooker James Segeyaro ruled out for four to six weeks with a knee problem.

Scans on Monday revealed the No.9 had suffered a grade two medial ligament tear in his left knee and would be sidelined for an extended period of time.

He suffered the injury in the second half of Saturday’s 24-12 loss to Canterbury.

It was the news coach Ivan Cleary would have been dreading with his side’s injury ward bulging at the seems.

He joins Matt Moylan on the long-term injury list with the side’s star fullback not due back from an ankle injury for another two months.

Centre Jamal Idris’ season is over because of a knee injury while Josh Mansour (knee) and Brent Kite (leg) are expected back soon.

The Panthers have suffered regular disruptions to their spine this year with Segeyaro, Moylan, Jamie Soward and Peter Wallace all spending time on the sidelines.

The Panthers are 11th on the ladder – one win outside the eight – however have failed to gain traction this season because of consistent injuries.

At the round 15 point, they have used 28 players – the second most of any team, only behind the Warriors who have fielded 29.

Apisai Koroisau will step into the Panthers No.9 role for the next several weeks after he returned from a shoulder injury against the Bulldogs.