Manu tasked with sparking Roosters' NRL form

Trent Robinson says Sam Walker's time in reserve grade has no end date as he turns to the versatile Joey Manu to ignite his side's attack.

Manu will start at five-eighth in a revamped Sydney Roosters side that faces St George Illawarra on Tuesday at Allianz Stadium.

Back-rower Angus Crichton has also been named to play his first NRL game since being diagnosed with bipolar disorder earlier this year.

Robinson is seeking an upturn in fortunes, given the Roosters have failed to score a second-half try in their past two outings and come into the Anzac Day encounter with a 3-3 record.

They have only scored 106 points in their first six games, their worst return since 2016 when they last missed out on a spot in the top eight. 

The decision to axe prodigious 20-year-old playmaker Walker gives Manu the chance to shift from the centres and be closer to the action.

Manu was the winner of last year's Golden Boot and Robinson was hoping that moving the Kiwi international into a spine role would spark their season into life.

"Joey's played enough footy, he's played enough footy in lots of different positions - centre, fullback, five-eighth," Robinson said.

"He's had roaming roles, he's got a great understanding of the players and the team around him.

"It's come quite naturally but we also need to give him the space there.

"(Halfback) Luke (Keary) has to take the responsibility to run that team and allow (Manu) to get into the game as he sees fit.

"Because even though he's played many games, we want to allow him to feel the game and express himself how he wants."

Robinson said he didn't have a "crystal ball" to determine how soon Walker would be back in contention for his starting team. 

The Queenslander played in the Roosters' NSW Cup side on Sunday.

"There was some things that he did really well and there were some things that I'd like him to improve on," Robinson said. 

The Roosters coach said Crichton would start his first NRL game since his diagnosis in February which caused him to miss the club's opening six fixtures.

Robinson said the forward's assertion he was gunning for NSW State of Origin selection indicated he was in a good space. 

"That's always been a part of him and his desire to be the best possible player he can," Robinson said. 

"If he's talking in those terms that means that he's really focused on playing and that means that his goals are very clear. That seems like a really good mindset to be in.

"I felt like the way that I've seen him train over the last month as well, he's hit his mark continuously. 

"So that's been really good to see and to get him out there to start, it was an easy choice actually."