The National Rugby League has blocked Newcastle hooker Danny Buderus from taking up a coaching role with Super Rugby club the ACT Brumbies.
Earlier, the Canberra-based rugby franchise announced the 34-year-old would travel to the nation's capital once a week to assist the Brumbies as their "collision coach".
His new role in teaching tackle-specific skills was described as his preparation for life after football as he enters his final NRL season with the Knights.
But the NRL weren't willing to authorise the position with their cross-code rivals, given salary cap conditions apply to all currently-contracted players.
Buderus earlier described his decision as a golden chance to get a start in the coaching ranks.
Buderus has played 242 games for Newcastle and was the last NSW captain to win a State of Origin series - back in 2005.