Sonny Bill Williams will not rule out finishing his career in the NRL when his contract with Kiwi rugby expires after their next World Cup in 2019.

“Pretty much as soon as I left rugby league we started that conversation,” Williams said on the Matty Johns Show.

“We came to the mutual understanding, the mutual agreement, you could call it a handshake agreement if you like, that if I do ever come back to rugby league it would be with the Roosters.

“When I decided to come back it was always going to be with the Roosters.

“Me and Nick go way back a long way, we’re like family. You don’t just win a premiership with somebody and then just close those doors.”

Williams has won premierships at the Sydney Roosters and Canterbury Bulldogs.