The Brisbane Broncos have been forced into a major change for Friday night's match against the Manly Sea Eagles in the second match of Magic Round.

Superstar fullback Reece Walsh has been made unavailable for the match due to knee soreness, which will see Selwyn Cobbo transition from the centres to the fullback role, per AAP.

His omission from the team will see ex-South Sydney Rabbitohs centre Josiah Karapani make his NRL debut alongside Kotoni Staggs in the centres, who will take the goal-kicking reigns and is vying for a spot for the NSW Blues.

This is the second team change from last week's team after Billy Walters (wrist) was sidelined and will be replaced by Tyson Smoothy in the dummy-half role, with Blake Mozer moving to the interchange bench.

Walsh's departure will see Josiah Karapani make his NRL debut after moving to the team in the off-season. Initially signed on a train and trial contract, he was promoted to the Top 30 roster before the start of the season.

Karapani grew up in New Zealand and has played eight games for the Burleigh Bears this season - the Broncos feeder club. In these appearances he has scored six tries, made 28 tackle busts, six line breaks, and averaged 153 running metres per game.