Payne Haas has reportedly signed a contract with the South Sydney Rabbitohs for the 2027, 2028 and 2029 seasons, though the club has only been able to lodge the paperwork with the NRL so far.
A mandatory ten-day cooling-off window now begins, giving Brisbane one last opportunity to persuade their marquee prop to stay.
"Haas has a big decision to make.
South Sydney are confident that they've got him but the Broncos still hold some hope.
They're going to offer him a five-year deal, but also with some clauses in there that if he would like to go to rugby union that is still an option."
Many in league circles had assumed Haas would only leave Brisbane if he intended to switch codes, making any rival NRL move unlikely.
Just a day before Souths announced the signing, reports suggested he might instead sign a short one-year extension with the Broncos upon returning from the World Club Challenge.
Now Haas faces a tight deadline to either reverse course or commit to the Rabbitohs, and longer, richer terms could sway him.
Journalist Danny Weidler has claimed Brisbane's offer was a significant undercut, describing it as 'considerably less' than his current pay.
Haas has always been clear money matters as he tries to support his extended family, which helps explain his search for better terms.
A lowball bid would not be surprising given Brisbane's belief they could retain him and mounting salary-cap pressure after major re-signings.
The club's recent deals for Reece Walsh and Kotoni Staggs are among the factors that have stretched the Broncos' cap close to breaking point.