Dave Howlett, Cronulla's pathways coach and leader of Endeavour Sports High's rugby league program, is joining Dean Young's Dragons staff for 2027.
Widely respected as a communicator, Howlett will bring experience as Young begins his first full season as an NRL head coach.
Nathan Fien is also leaving the Dolphins to become Young's deputy, The Daily Telegraph reports.
Fien joined the Dolphins before their inaugural season under Wayne Bennett and helped build a potent attack.
The team ranked first in attack in 2025 and fourth in 2026, then reached the preliminary final in its first finals campaign.
St George Illawarra averaged 16 points per game and ranked last across major attacking statistics.
Six recruits are due to arrive for 2027: Scott Drinkwater, Keaon Koloamatangi, Luke Metcalf, Connor Watson, Phillip Sami and Kodi Nikorima.
The major roster overhaul could continue when the free-agency window opens on November 1.
Young will enter his first preseason as full-time coach with more talent and experience, while developing young players.
The club has extended Ryan Couchman, Toby Couchman, Dylan Egan, Jacob Halangahu, Loko Pasifiki Tonga, Hamish Stewart and Jacob Webster.