Brisbane Broncos prop Thomas Flegler has been ruled out of this weekend's pre-season clash with the Gold Coast Titans in Cairns.

Flegler, who played 18 games for the Broncos last year, spending two stints off the park with suspension, is off-contract at the end of the 2023 season and likely to receive big bids from rival clubs interested in attracting the firebrand forward out of Red Hill.

But his contract year has started shakily, with a head knock at training ruling him out of Sunday evening's clash against the Titans, which is the second of a double-header in the North Queensland city, with the Cowboys to play the Dolphins in the earlier game.

Flegler will be replaced in the side by Logan Bayliss, who had originally been named on the bench and is yet to make his first-grade debut, although will continue to push to do so this year after more strong performances in the QLD Cup in 2022.

Bayliss-Brow's bench spot will be taken by young gun Brendan Piakura, who will push for time in first-grade this year after battling injury for much of the 2022 campaign.

RELATED: Pre-season challenge Week 1 team lists

Rated as one of the best young forwards in the game, Piakura has played two first-grade games, with one in each of the last two seasons, but is likely to push for more consistent minutes this year if he can stay on the park, with TC Robati currently having stood himself down over off-field matters.

The Broncos and Titans' trial will be the final of Week 1 in the NRL's new pre-season challenge, played at 8:05pm (AEDT) on Sunday.