Penrith’s semi-final hopes have been dealt a massive blow with halfback Peter Wallace ruled out for the rest of the NRL season with a ruptured ACL.

Wallace injured his right knee in the Panthers’ loss to Cronulla in Bathurst on Sunday.

The game was Wallace’s first game back from a two-game stint on the sidelines due to an injury to his left knee.

He left the field midway through the first half but returned to the field, hobbling through the rest of the game.

Wallace has been instrumental in the Panthers’ rise to a top four side this year.

The Panthers are facing an injury crisis in their halves.

Wallace will join fellow playmakers Isaac John (achilles) and Tyrone Peachey (pec) on the sidelines for the rest of the season.