South Sydney skipper Roy Asotasi has suffered a heavy head knock late in the first half of the Rabbitohs clash with Penrith at CUA Stadium.
Asotasi walked gingerly off the field in the 38th minute after attempting to make a tackle near the halfway line and has not emerged from the sheds after the halftime break.
Hooker Issac Luke has also left the field with a suspected broken hand.
It had been a difficult opening 40 minutes for Souths, as they went into the change rooms trailing 22-6.
Fellow prop Michael Greenfield walked off the paddock after just 18 minutes when he was crunched in the rib cage by Panthers backrower Frank Pritchard.
Greenfield complained of having trouble breathing and while he remains on the interchange bench, and has only just returned to the field.