Canberra coach Ricky Stuart has backed Cornish, only nine games into his NRL career, to rise to the challenge against Golden Boot winner and New Zealand Warriors playmaker Shaun Johnson at Canberra Stadium.

Cornish is among a horde of NRL halfbacks off-contract at the end of the season and Daly Cherry-Evans' move from Manly to the Gold Coast Titans next year has the potential to spark a chain reaction of changes around the league.

Manly's Kieran Foran, Sydney Roosters pivot James Maloney, Bulldogs playmaker Trent Hodkinson and Parramatta's Chris Sandow are among the high-profile halves off-contract at the end of the year.

Cornish has said his priority is to remain a Raiders player for life but his manager, Paul Sutton, said talks had been delayed until the Goulburn product can establish himself in the NRL.

Cornish beat Sam Williams to first crack at the No.7 jersey and took his chance with a composed display in last week's win at Cronulla, his kicking game particularly strong.

"He needs to play some NRL, stay there and see what his full value is in the game," Sutton said.

"He's only had four starting games. He needs to get some games under his belt."

Cornish has the perfect chance to boost his bargaining power on Sunday against Johnson, crowned as the best player in the world last year.

Johnson has tormented the Raiders in seasons past, scoring a total of five tries and 52 points in his past two games against Canberra.

Johnson has been savaged by the media for his lacklustre effort in the round one loss to Newcastle, coach Andrew McFadden labelling his game "disappointing".

Stuart expected Johnson to lift, but backed Cornish to accept the battle.

"Knowing Mitch how I do, he'd be looking forward to the challenge," Stuart said. "It's a good way of him having a look at where his game is.

"I know all young guys like to compare themselves to the great players, [and] Johnson's one of the best halves in our game. He burns the edges of defence with his speed; he didn't win that award last year for no reason.

"He's been heavily criticised this week, which I think's unfair. He'll come out for a big game."

Johnson is a big step up on the players Cornish has faced in his short NRL career. So far the former Australian Junior Kangaroos captain has gone head to head with Cronulla's Jeff Robson (twice), Parramatta's Chris Sandow and Wests Tigers youngster Mitchell Moses.

Raiders utility Josh McCrone insisted Cornish would not be intimidated.

"Mitch is a pretty confident bloke and he should be at this stage," McCrone said.

"He steered our ship really well last week, his kicking game was spot on.

"Johnson would be his own biggest critic. I'm sure he knew it wasn't his best game and he was down in a couple of effort areas. He'll be pretty hungry to prove he's the player he is."

Raiders skipper Jarrod Croker said Cornish's defence had been his biggest area of  improvement.

"It'll probably be a bit tougher this week for a lot of us. There'll be those big boys running at us hard and he knows he'll get plenty of traffic, as most halfbacks do."

"One thing's for sure, Shaun Johnson won't play two bad games in a row.

"The Warriors have copped a fair bit of criticism so they're going to be fired up. They'll be a completely different team from round one."