North Queensland forward Coen Hess will miss the 2024 NRL season after scans confirmed he had suffered a season-ending knee injury.
The 27-year-old ruptured the anterior cruciate ligament (ACL) in his right knee in the trial clash with Canberra on Sunday.
Cowboys general manager of football Micheal Luck told AAP the club may investigate signing a replacement for Hess as they have two roster spots available in their top 30.
Hess has been an excellent performer for the Cowboys in 165 NRL games since his debut in 2015.
He has also represented Queensland on six occasions in State of Origin football.
Hess played every game of the 2023 campaign and was equally strong as a second-rower and middle forward.
The Cowboys are in camp in the NSW town of Kiama where Hess underwent a scan on Wednesday.
"It is terrible news for Hessie," Luck told AAP.
"He is as professional as anyone in our building. He will have his surgery, be methodical about his rehab and no doubt he will be bigger and better next year.
"It is a big hole for us to fill this year and will give an opportunity for some guys to step up.
"We have also got a couple of roster spots spare we could potentially back-fill if we need to later in the year."
The Cowboys have good depth in their squad and Luck said the trials had showcased potential replacements for Hess.
"There are some guys who have trialled really well who probably weren't on a lot of people's radar before the pre-season," Luck said.
"Sam McIntyre and Thomas Mikaele have both been very good in the pre-season and will be given a bigger opportunity than they would have been earlier in the year now in Coen' absence.
"It means (prop) Griffin Neame has got to continue his evolution and we expect him to be a long-term player for our club.
"He gets the chance this year to take more of a leadership role, a year or two before he thought he might have to."
The Cowboys open their NRL campaign with a round one clash against the Dolphins at Suncorp Stadium on March 10.