The NRL are confident the State of Origin series opener in Melbourne will attract more than 80,000 fans.

More than 50,000 general public tickets have been sold so far for the June 6 clash at the MCG, which does not take into account corporate boxes or the large MCC members area.

It comes after an Origin record crowd of 91,513 attended the last Origin clash in Melbourne in 2015.

The fixture is already scheduled to return to the venue in both 2021 and 2025 as the league continues their preference for one neutral venue each year.

"We are expecting a crowd of more than 80,000 at the MCG on June 6," an NRL spokesman told AAP on Sunday.

The NRL's confidence comes despite Melbourne favourite Cameron Smith having announced his retirement from representative football a fortnight ago, following in the footsteps of Queensland legends Cooper Cronk and Johnathan Thurston.

Billy Slater, Will Chambers, Cameron Munster and Felise Kaufusi are still likely to form a quartet of Melbourne players in the Maroons team while likely skipper Greg Inglis remains a favourite from his time at the club.

Perth will host an Origin game in 2019 and Adelaide in 2020 before the series returns to Melbourne.