Newcastle star Fletcher Sharpe has been diagnosed with a lacerated kidney after being admitted to hospital in Perth.
Sharpe reported abdominal soreness after suffering a concussion in the Knights' 26-20 win over the Dolphins in Perth on Saturday.
It is understood he suffered the damage in the same tackle as the concussion, when his body hit the ground hard when brought down from behind.
The five-eighth has since been taken to hospital, and is set to remain in Western Australia for several days as he deals with the issue.
Sharpe would already have missed Friday night's clash with Canberra due to concussion issues. The Knights have a bye the following week.
Newcastle do not yet have a timeline on how much longer they expect the 21-year-old to miss.
Sharpe has been one of Newcastle's best threats this year, scoring 11 tries and setting up another three in a side that has the worst attacking record in the NRL.
Newcastle have several back-up options in the halves, with Tyson Gamble available again and Jackson Hastings having returned to the NRL against Manly this month.
Elsewhere, there are fears Dolphins winger Jack Bostock suffered a dreaded ACL rupture in the Perth match.
The potentially season-ending injury comes just a week after the flyer scored four tries against North Queensland last Saturday.
The Warriors are also waiting on scans on halfback Luke Metcalf's quad and winger Dallin Watene-Zelezniak's ankle after their loss to Penrith.
Watene-Zelezniak is expected to be sidelined for some time with a syndesmosis injury, but the fourth-placed club hold some hope that Metcalf's is not serious.
