Raiders membership numbers have jumped to 19,319 this week - the highest tally in the Green Machine's rich history - despite a drop in average crowd numbers so far this year.

The membership rise comes as details emerge of a renewed push for the ACT government to invest in a $350 million stadium with a roof in Civic to get Raiders and ACT Brumbies fans back into the stands.

A group of businessmen have drawn plans for a stadium and a convention centre in the hope of fast-tracking the development, which has been delayed for almost a decade.

But a realistic timeframe for planning and construction of a new undercover venue would be at least five years away, meaning the Raiders and Brumbies are desperate to engage fans in other ways.

The Raiders have capitalised on an NRL popularity boom and have found new ways to entice fans to become members, including $1 million giveaways, the viking clap and reconnecting with the club's history.

"A few years ago we were only scratching out 10,000 members ... to almost double that in the space of three seasons sings volumes for what the club has been able to do in terms of better engagement," said Raiders commercial manager Jason Mathie.

"It was a bit optimistic three years ago, but we said we would get 20,000 members by the end of 2018. I'm quietly confident we will do that.

"...It would be fantastic [to get more people to games]. Of the ticketed members we have, which is just over 80 per cent, we're only getting about 50 per cent of those people coming to games.

"There is plenty of scope for growth on game-day attendance, which is something we definitely need to work on."

The ability to add junior players to the membership tally has helped boost Canberra's numbers in recent seasons.

The Raiders were averaging 9000 fans per home game in 2014 and 2015, but attendances swelled to more than 14,000 last year. They were the best average attendance figures since 1995.

A combination of low-drawing teams and inconsistent form has seen that number drop to 11,977 in five games so far, but the club is hopeful of people coming back through the gates.

"You've got to keep chipping away and have conversations with people absorbing our product," Mathie said.

"The changes we made were not just about promoting the game of football, but giving people the opportunity to come here [for different reasons]."

The Raiders lost their first four games of the season, but have bounced back to form to win four of their past six matches.

They play the top of the table St George Illawarra Dragons in Mudgee on Sunday and have a chance to claim their biggest scalp of the season so far.

Coach Ricky Stuart made just one change to his extended squad for the clash, with halfback Sam Williams in contention to return from injury. Blake Austin trained with the Raiders on Wednesday after injuring his ankle last weekend.

"It would be great to have [Austin] out there, hopefully he pulls up OK and he can play this weekend," said winger Nick Cotric.

"[The Dragons] are a great team, we have to be on top of our game and get the little things right."

The Raiders will return to the capital to play against the Manly Sea Eagles in a 6pm timeslot on May 25, with more than 70 former players set to be honoured as part of Canberra's "Forever Green" initiative.

NRL ROUND 11

Sunday: St George Illawarra Dragons v Canberra Raiders at Glen Willow Oval, Mudgee, 2pm. TV time: Live on Fox Sports 2.

Raiders: 1. Jack Wighton, 2. Nick Cotric, 3. Jarrod Croker (c), 4. Joseph Leilua, 5. Jordan Rapana, 6. Blake Austin, 7. Aidan Sezer, 8. Iosia Soliola, 9. Siliva Havili, 10. Shannon Boyd, 11. Joseph Tapine, 12. Elliott Whitehead, 13. Josh Papalii. Interchange from: 14. Ata Hingano, 15. Luke Bateman, 16. Charlie Gubb, 17. Dunamis Lui, 18. Liam Knight, 19. Michael Oldfield, 20. Sam Williams, 21. Craig Garvey.

Dragons: 1. Matthew Dufty, 2. Nene Macdonald, 3. Euan Aitken, 4. Tim Lafai, 5. Jason Nightingale, 6. Gareth Widdop (c), 7. Ben Hunt, 8. James Graham, 9. Cameron McInnes, 10. Paul Vaughan, 11. Tyson Frizell, 12. Tariq Sims, 13. Jack De Belin. Interchange from: 14. Jeremy Latimore, 15. Kurt Mann, 16. Leeson Ah Mau, 17. Blake Lawrie, 18. Reece Robson, 19. Zachary Lomax, 20. Mitchell Allgood, 21. Hame Sele.