Spencer Leniu has lifted the lid on the no-holds-barred training sessions that saved the Sydney Roosters' season, after a week of players brutally bashing each other.

Written off after weeks of injuries, the Roosters manhandled Manly in the middle to lay the foundation for a 40-16 win and a ticket to the preliminary final.

The Roosters are well aware they must take a similar baseball-bat style approach to Melbourne on Friday night, against a team they have beaten only once since 2020.

But with the Sea Eagles nursing sore bodies on a six-day turnaround for Saturday night, Leniu said the Roosters had their most bruising week of training.

"It was one of the hardest weeks we'd had, almost pre-season vibes," Leniu said.

"After that Penrith (qualifying final), all the boys came in and took their medicine and really ripped into each other. We flicked that switch.

"It was literally (no holds barred). We were really physical out there (against Manly), and that was a reflection of how we trained."

Leniu said that approach had been led by Jared Waerea-Hargreaves on return from a suspension.

It then carried over onto the field, with Waerea-Hargreaves damaging in the first stint of what would have been his last NRL game had the Roosters lost.

"That's just how we have to prepare for these games. And finals games are win at all costs," Leniu said.

"If that means we have to bang each other at training, then we have to bang each other at training.

"That training intensity won't be any different this week. It's a short turn around, but we'll rip in to each other again and hopefully rip in against the Storm on Friday."

Second-rower Angus Crichton said the sessions had been prompted by the Roosters' poor 30-10 loss to Penrith in the first week of the finals.

"We were all sort of feeling it, the boys were sore and looking at each other saying, 'What are we doing?'," Crichton said.

"But you train how you want to play and we know we missed our mark last week against Penrith.

"We knew we had no other option but to make sure we didn't miss our mark this week."

Saturday's match was effectively over in 23 seconds, after Manly centre Tolu Koula was knocked out trying to tackle Waerea-Hargreaves and Jake Trbojevic followed him off for a HIA in the next hit up.

"It was brutal: Knockout, reset, knockout, rest," Crichton said.

"And I was taking that third one (carry). I was like, 'Surely not another one, just get through without a knockout'."

The other big win for the Roosters was lock Victor Radley getting through unscathed, scoring the first try after returning from a fractured scapula in just three weeks.

"It's unbelievable. He's a mad unit," Leniu said.

"The whole week he is like: 'nah, just chuck an injection in, numb it up and I'll be right'.

"That's what he was saying all week and I was like, maybe just chill, we'll win this week and you come in next week.

"But it's a credit to him. He's just a hard person, hard-nosed. He makes me feel 10-feet tall like Jared and all the other boys."