Tongan international Siliva Havili has emerged as the front-runner to full Hodgson's No. 9 jersey, but the halves are also posing a selection headache to Stuart.

Sam Williams could force his way into the starting team for a clash against the Gold Coast Titans on Sunday night, but he's competing with the incumbent pairing of Blake Austin and Aidan Sezer.

Stuart will name an extended squad on Tuesday afternoon as the Green Machine prepare to begin their bid for finals redemption.

Hodgson will be missing for the majority of the season after rupturing his anterior cruciate ligament playing for England in the World Cup at the end of last year.

His injury opened the door for Havili and Craig Garvey to get their opportunity to step up.

Rugby league Immortal Andrew Johns called on Austin and Sezer to take control of the Raiders, admitting it's almost impossible to replace international star Hodgson.

The Raiders lost eight games by six points or less in 2017, which ultimately sounded the death knell on their season, so the chance is there for Sezer and Austin to stand up.

"You can't cover a player like [Hodgson] because he is so creative, his kicking, he's smart with the ball," Johns said at the Channel 9 NRL season launch in Sydney.

"I know they've got a couple of younger hookers but they are more runners than players so it puts more pressure on Aidan Sezer. He'll have to take more responsibility but you can't cover a player like [Hodgson].

"[Sezer and Austin] both have to stand up, they both have to take more responsibility. I've seen in the off-season Aidan talking about he wants to run the ball more, so time will tell.

"I think they're aware of it, so I'm sure Ricky has challenged them as players. Not only them two, everyone else has to just improve that little bit without Josh being there.

"It's a big ask but the Raiders have shown if they get on a roll that they're hard to stop."

Sezer enjoyed a stirring return to form during Canberra's ill-fated run to the finals last year but the 26-year-old has been hot and cold during his first two years at the Raiders.

He spent the bulk of his four seasons at the Titans playing five-eighth, and Johns' fellow Immortal Wally Lewis says the shift to halfback has slowed his development.

But Lewis believes there is "a definite change" in Sezer's game just around the corner.

"I was a big fan of Aidan's while he was at the Coast, I used to go and watch all of those games and they were fantastic," Lewis said.

"I think with the shift in position, he was a quality five-eighth, he moves to play at No. 7 and there is a definite change in his game coming and it does take a while.

"They are two completely different positions. At five-eighth you are standing there and you are getting time to read the play, you're getting plenty of space available for you.

"At No. 7 you're in the middle of the action screaming at the dummy half if you want the ball or telling the forward what to do to get them out of your way.

"It's a little more complex, and can take some time. I think he's certainly got that and he's got a fair coach in Ricky to be able to assist him in his change."

Johns says "something needs to be done" about players injured on representative duty, and NRL boss Todd Greenberg says salary cap relief could be in place by the mid-season Test in the United States.

Canberra hoped for salary cap dispensation to sign another player but the NRL declined their request in a move Johns labelled "terrible", pointing to what the uproar would be like if it happened to Cameron Smith or Johnathan Thurston.

"I really felt sorry for the Raiders and Ricky. He's one of the best players in the world, you lose your best player," Johns said.

"They buy the player, they make him the player he is, then they release him for rep footy and then he gets injured not on their watch. I felt sorry for them."