South Sydney chief executive Blake Solly says Thomas Fletcher will always be welcome at the club.
The 22-year-old second rower has been released from the final year of his NRL contract to take up an extended opportunity with another NRL club.
Fletcher made his NRL debut against the Broncos in 2025 and has played seven NRL games.
"Tom debuted at the Club, fulfilling a childhood dream to play for South Sydney, and has been a fantastic contributor to the Club over the past four seasons," Mr Solly said.
"We wish him and his family all the very best in the future and 'Fletch' will always be regarded as a Rabbitoh."