Adam Reynolds, who is retiring as captain, said Brisbane teammates were stunned when Payne Haas confirmed he had signed with South Sydney.
Reynolds rejected suggestions the departure was caused by a falling-out with coach Michael Maguire, insisting that was not the motivation.
The Rabbitohs reportedly landed the game's top prop on a three-year contract worth $3.6 million, a deal that surprised many around the competition.
Players from both clubs spent time trying to understand why one of the elite front-rowers would walk away from the reigning premiers.
Rival club officials speaking on the condition of anonymity said there had been talk Haas had grown tired of Maguire's intense training methods.
Those same anonymous voices added speculation that the forward might prefer a reunion with Wayne Bennett, the coach who brought him to Red Hill a decade earlier.
Souths received further good news as their coaching situation looked to be stabilising amid the high-profile signing.
Bennett is reportedly close to agreeing to a one-year contract extension which would keep him at Souths until the end of 2028.
If the extension is finalised, it would effectively end the possibility of the 76-year-old becoming the inaugural coach of the PNG Chiefs.
Reynolds' public remarks appeared aimed at reassuring teammates and fans while speculation about the move continues to swirl.