Under-fire NSW five-eighth James Maloney has promised his Sydney Roosters teammates he'll end his form slump with a big performance against Cronulla this Saturday.

The struggling NRL premiers face a Sharks side that's lost five of their opening six games on the back of three successive losses including last week's 14-12 defeat to a rejuvenated Parramatta.

Maloney has been widely criticised for his recent performances especially against the Eels where an intended pass to Roger Tuivasa-Sheck late in the game flew straight into the crowd with the winger poised to score.

Star prop Jared Waerea-Hargreaves revealed Maloney's vow on Thursday and backed the former Warriors playmaker to get back to the form that earned him State of Origin selection for NSW last year.

"Jimmy has been great," Waerea-Hargreaves said.

"He spoke up earlier this week and said he needs to pull a bit more weight around.

"But I think he's been playing well.

"After he spoke up another 16 of us did the same.

"I then said to the boys 'I know I need to have a big one this week and everyone sort of said 'sweet, so do I.'"

The Roosters were hot favourites to become the first team since Brisbane in 1993 to win back-to-back united competitions.

However, they have found their title defence less than plain sailing with Waerea-Hargreaves saying teams are raising their games in a bid to claim their scalps.

Despite their struggles, Waerea-Hargreaves said coach Trent Robinson has maintained his calm and believes that approach will pay dividends.

"When Robbo talks everyone listens, it's just the respect everyone has for him," he said.

"He's a very calm guy. But you know when he means business, he has this look in his eye.

"He's definitely got the best out of me, I can say that for a few others in the team as well.

"But we need to go out there and do it this weekend and that is all down to us players."

A loss to Cronulla would sound alarm bells at the club and Waerea-Hargreaves admits they couldn't have chosen a harder side to break their barren run against than the Sharks.

The Roosters have won only four of the last six meetings between the sides and not tasted victory at Shark Park since 2009.

"They'll be super keen, especially after losing to Manly last week," Waerea-Hargreaves said.

"I've never won there in my career. It's a very hard place to play.

"I don't think I've ever not played there when it's not chucking down with rain either."