The Sydney Roosters will be without injured key men Jared Waerea-Hargreaves and Joey Manu as they plot to bounce back from a hefty loss to Penrith that captain James Tedesco lashed as "embarrassing".

The Panthers put in their best performance of the season on Friday to demolish the Roosters, who leaked four tries in each half and fell 48-4. In 103 previous meetings, the Panthers had never won so convincingly.

The Roosters were restricted to only one try for a second-straight week and lacked steel in defence, especially once Penrith's Jarome Luai found his groove.

Tedesco and coach Trent Robinson lamented the Roosters' inability to win the effort areas of the game.

"We pride ourselves on that at the Roosters, working hard for each other. The last few weeks, it hasn't been there," Tedesco said.

"It was really hard to be captain and serve that up. It's embarrassing.

"We're not resilient enough.

"As soon as something bad happens, we let in a few tries. We just drop our heads and it just gets worse and worse. It's pretty hard to swallow."

Injuries to Waerea-Hargreaves and Manu compounded the Roosters' woes, with both men set for scans over the weekend.

"How bad (the injuries are) I'm not sure, but they obviously couldn't come back on the field," Robinson said.

Waerea-Hargreaves left the field with a pectoral injury in the opening 20 minutes and his teammates floundered without him; no Roosters forward ran for over 100 metres, but five of their Panthers counterparts managed to.

Pec injuries can result in months rather than weeks on the sidelines but Robinson did not believe the prop's injury was severe.

"I don't think it was ruptured," he said.

Manu required assistance leaving the field in the second half after he rolled his ankle attempting to stop the Panthers' team defence from carrying a Roosters ball-carrier backwards.

The New Zealand international has played five-eighth for the past month, with Sam Walker dropped to reserve grade, but a knee injury has meant out-of-favour Walker won't regain his spot in the side to face St George Illawarra next week.

Walker suffered his injury at training earlier in the week and missed Friday night's NSW Cup game against Penrith but will not require surgery and is expected to be available for selection in round 14.

"It's not that bad, it's a couple of weeks in a brace. Post (round 13) bye would be when I think he's going to come back," Robinson said.

Robinson remained calm amid the injury scares, insisting his side had the depth to cover for both Waerea-Hargreaves and Manu.

"But it's not about individuals, it's about us collectively, as a whole crew, getting it fixed pretty quickly and getting back to some Roosters style of footy," Robinson said.

Drew Hutchisonis the likeliest candidate to partner Luke Keary in the halves against the Dragons, while Terrell May appears as a strong chance of coming onto the bench as a middle forward option.