North Queensland are bracing for at least six weeks without Heilum Luki after scans confirmed the second-rower would require surgery on his left ankle.
Luki limped from the field early in the Cowboys' golden-point win over Newcastle, after being injured attempting to make a last-ditch tackle.
The 22-year-old was later spotted with his foot in a moon boot, and Cowboys officials have since confirmed to AAP that Luki will require syndesmosis surgery.
Luke is expected to miss between six and eight weeks recovering from the surgery.
The Cowboys had youngster Kulikefu Finefeuiaki play 58 minutes off the bench on Saturday night after Luki's injury, and he would be expected to start in place of him.
Luki's surgery continues a frustrating run for the Cairns junior, whose past two seasons have been disrupted by injury since his debut in mid-2021.
North Queensland had previously released edge forward Luciano Leilua from the final two years of his contract last month, allowing him to complete a move to St George Illawarra.