North Queensland back-rower Heilum Luki will miss the remainder of the NRL season after suffering an anterior cruciate ligament injury.
Luki left the field 15 minutes into the Cowboys' 31-12 home victory over St George Illawarra on Friday night after injuring his right knee in a tackle.
Scans on Saturday confirmed a torn ACL and the Cowboys said Luki would have surgery.
After losing fellow back-rower Mitch Dunn to the same injury earlier this season, coach Todd Payten said it's tough for the club to have two of their premier young players guns sidelined.
"It's never good," Payten said after their win on Friday.
"But we've worked really hard as a squad and we'll have Jeremiah (Nanai) more than likely this week, fingers crossed, or the weekend after.
"The whole squad is working hard and we're working them hard. That's what they're working hard for is an opportunity, and it might present itself.
Luki played in all 14 of the Cowboys' games this season, scoring four tries.
