Hull FC has signed up 6,000 season members, reaching two-thirds of last year's total less than a month after memberships went on sale.
The club expects to sell out before the season begins in February, as Daly Cherry-Evans prepares to join on a one-year deal.
Cherry-Evans, 37, will move to the UK with his family after ending his 379-game NRL career with the Roosters' grand final victory over Newcastle earlier this month.
His name has nevertheless surfaced as a possible replacement for Sydney's Sam Walker, after Roosters chairman Nick Politis told Walker he could find another club when contract talks broke down.
Cherry-Evans has no intention of abandoning his Hull agreement, despite reversing a move to the Titans in 2015 to stay with Manly.
Announcing his Hull move, Cherry-Evans said: "I still have a real desire to play and compete, so the opportunity to join Hull FC and experience the Super League is something I'm genuinely excited about."
"I've always had that curiosity of what Super League would look like."
He added: "Talking to my wife and the people we love and trust within the circle, we were told we would never regret going over to the UK, to the Super League."
"We're excited about what's ahead for us as a family and I'm also very excited about the challenges that Super League's going to give me."
Hull FC promoted the opportunity to watch him in 2027, calling him "one of the sport's modern greats" in its membership pitch.