Signed on a four-year-deal a fortnight ago, Douehi was brought to the club to battle Thompson for the No.1 jersey but skipper Moses Mbye believes he's up for the challenge.

"I haven't spoken to him about it but Corey's got a great attitude towards football and a great attitude towards training so I think he's going to really relish and enjoy the competition," Mbye said.

"It's healthy. It's what you need. I think all the clubs who are successful have depth and that's certainly what we have now."

Signalling the end of a long off-season, the Nines were launched in Perth on Thursday to the relief of fans craving action.

Brisbane, North Queensland, Penrith, Parramatta, Cronulla and Wests Tigers are among the favourites for the title and boast the strongest squads across the two-day tournament at HBF Park starting Friday.

The Panthers will unleash a near full-strength team including a new-look spine of Nathan Cleary, Jarome Luai, Dylan Edwards and Apisai Koroisau.

The Eels, who have won 14 of 20 games in four Nines tournaments including the 2016 title before it was stripped for salary cap breaches, have picked boom recruit Ryan Matterson.

His inclusion compliments a mobile side that also features Clint Gutherson, Mitch Moses, Maika Sivo and Blake Ferguson.

The tournament will kick off with the Panthers taking on the under-strength Roosters on Friday afternoon.

With the majority of the first-grade squad in England for the World Club Challenge, the Tricolours have just one established NRL player in their squad in Sam Verrills.

Each team will play two pool games before the top teams advance to the finals on Saturday afternoon.

Fans will also get the first taste of a new rule change for the 2020 season proper with the 20/40 rule on show.

It joins a list of adaptions for the Nines format including five-tackle sets, drop goals for conversions, unlimited interchange and five-point tries scored under the posts.

Australian Associated Press