The 2021 NRL season of stand-in Brisbane captain Patrick Carrigan is over due to a knee injury suffered in last Saturday's 19-18 loss to North Queensland.
The 23-year-old went down in back play early in the second half of the Queensland derby in Townsville and scans have confirmed he has ruptured an anterior cruciate ligament (ACL).
It means the lock will meet with a surgeon this week with surgery the most likely option.
Carrigan was leading the Broncos against the Cowboys with captain Alex Glenn already sidelined by a calf tear.
With Glenn still up to three weeks away from a return, coach Kevin Walters will have to turn to another of his players to take on the captaincy ahead of this weekend's Magic Round clash with Manly at Suncorp Stadium.
Those potentially in the mix to lead the Broncos include playmakers Jake Turpin and Anthony Milford or forwards Payne Haas, Matthew Lodge and Tevita Pangai Jnr.
