Penrith centre Tyrone Peachey is facing a stint on the sideline after suffering a fractured rib.
Peachey played on after copping a knock in Saturday's 28-6 loss in Melbourne, but scans have since revealed the fracture.
It's at this stage unclear how long he will be sidelined, but it is confirmed he will not be available to face South Sydney on Friday night at Pepper Stadium.
Panthers general manager Phil Gould confirmed the injury on Twitter.
"Fractured rib. He will be missing for a while," he tweeted.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Peachey's absence will be a massive blow to the eighth-placed Panthers, considering he has been one of their best outside backs this season.
He has already scored three tries in five matches, and is averaging 145 metres per match - 39 more than he did last year.
However the Panthers have extensive cover in the outside backs.
Peta Hiku is already playing off the bench, while Kangaroos winger Josh Mansour is sidelined with a knee injury for another two months.
Meanwhile lock James Fisher-Harris is on schedule to return from a fractured cheekbone on Friday.
It's understood the 21-year-old will still have to overcome checks this week before getting a full clearance to play.
Second-rower Bryce Cartwright is also struggling to return from an ankle injury.
