Even Manu's superstar teammates are in awe

An awestruck Cooper Cronk joked that he's unable to grasp a tennis ball like Joey Manu effortlessly handles the footy.

Manu toyed with South Sydney at the Sydney Cricket Ground on Friday as the Roosters claimed a 30-6 win and booked a place in the preliminary final with their opponent yet to be determined.

The powerful centre did extremely well to ground the Steeden with his right mitt to open the scoring and later produced a special flick-pass with the same hand to set up a brilliant try.

"Some of those passes last night - I can't even hold a tennis ball in one hand but what he was doing with the footy, it's pretty impressive," Cronk marvelled.

Cronk, who will retire at season's end after 16 years in the top grade, said his role as a halfback has become far simpler thanks to the likes of Manu.

"It's funny, these kids just get bigger, stronger, faster. It makes our job in the middle in terms of the ball-playing part of it a little bit easier because you've just got to create a little bit of space," Cronk said.

"I remember when I first started, you had to create a mountain of space or you had to put guys through complete holes. Whereas now guys only need a couple of inches, a couple of millimetres to do what they do."

Five-eighth Luke Keary agreed there's no need to do too much with such strike on the fringes.

"We've got some quality players - we want to try and get them the ball as much as we can," Keary said.

"Latrell [Mitchell] and Joey - you saw Joey at the start there when we fed him a bit of early ball. Then we kind of brought Latrell into the game at the back-end."

The defending premiers will enjoy a well-earned rest next weekend to prepare for the grand final qualifier.

Cronk has two matches maximum left in his illustrious career but said he isn't bothered about a personal fairytale.

"I don't really care when my last game is. It could have been last month, it could have been the weekend or whatever it is. What I do care about is when it's this football club's last game," Cronk said.

"This club has been tremendously good to me, both the football club and the people involved with it, so I'll be doing everything I possibly can to make sure this football club has a smile on its face on our last day."

Having piled on 26 points in the first stanza against the Rabbitohs, the Roosters managed only one try in the second term and coach Trent Robinson lamented missing the chance to rack up a bigger margin.

Cronk admitted the Tricolours should have kept their foot on the pedal but was pleased with the overall display.

"I suppose as professional athletes we all strive for perfection, don't we. We always achieve something then try to keep taking the ceiling higher and higher," Cronk said.

"The only person that's ever really got close to perfection is probably Don Bradman. Everyone else is trying to chase it.

"No matter what our performance is, we'll continue to work hard, continue to improve the areas we need to, and come that whistle whenever we play we go out and compete in the Roosters style for all the supporters and members."

However, Keary said the team still have shortcomings to address.

"We're going to get some work done. We'll have a normal-ish week and then have a day or two off over [next] weekend just to freshen up," Keary said.

"A couple of boys will rest a few niggles but we've got some work to get done before the prelim. We know we're not quite where we need to be."

A self-described "footy-head", Keary plans to tune into the other finals matches for enjoyment.

"I know some of the boys mightn't. I'll more watch it as a bit of a fan rather than studying or anything like that," he said.

The Roosters are set to lose prop Jared Waerea-Hargreaves for their upcoming game, with the enforcer facing a one-week ban after being charged with a grade one trip on Souths centre James Roberts.