The Broncos halves stocks may have got thinner on the ground with fears halfback Sean O'Sullivan suffered a season-ending knee injury on Sunday.

In the closing stages of Norths Devils' 24-20 elimination semi-final loss to Easts Tigers in the Intrust Super Cup, the 21-year-old was preparing to take a pass when his left knee gave way with no-one around him.

Channel Nine commentator Scott Sattler said he hit the ground "like a sniper shot him" as O'Sullivan called immediately for the trainer who did an ACL test on his knee.

O'Sullivan hobbled off the field and took no further part in the game and is set for scans on Monday. Brisbane club officials are yet to make any official announcement.

The Broncos, who will play the Eels in an elimination semi-final on Sunday, are already without teenage half Tom Dearden (ankle) for the rest of the season and former Cronulla five-eighth Jack Bird is on his way back from a knee reconstruction and will not play again until next year.

Finals Snapshot: Broncos

Meanwhile, Brisbane captain Darius Boyd expects the Broncos to thrive in the face of adversity as the only remaining Queensland-based team.

"[It's] backs against the wall a little bit this week going down to Parra," Boyd said,

"Probably no one gives us a chance to win as well and we seem to play our best then."

Boyd admitted the side's attitude wasn't up to scratch in their loss to the Bulldogs on Saturday.

"It was one of those games everyone expects you to win and [we were] probably thinking about the finals next week even though we weren't assured of a position," he said.

Boyd lauded Brisbane's fortitude to fight back from a horrid opening to the season.

"No one gave us a chance to make the finals after the start we had. I think internally the players and coaching staff have done a great job to get where we are," he said.

Brisbane coach Anthony Seibold is expected to name Boyd and Jake Turpin in the halves against the Eels but his options should one of them get injured are few.

Queensland under 20s half Cory Paix is fully recovered from an ankle injury and played 31 minutes in the Redcliffe Dolphins 25-24 win over Tweed Heads on Sunday and is available for selection for the Broncos.

Troy Dargan, who partnered O'Sullivan in the halves for Norths and is bound for the Rabbitohs in 2020, is also an option.