The Sydney Roosters will have three new headaches to deal with on the injury front following their heavy 48 points to 4 loss against the Penrith Panthers on Friday evening at the foot of the mountains.

Two of those injuries came out of the game, with both Jared Waerea-Hargreaves and Joseph Manu failing to complete the contest and possibly looking at time on the sidelines.

Meanwhile, Sam Walker has also sustained a knee injury at training, not taking part in the NSW Cup game earlier in the evening against the Panthers.

Robinson confirmed at his post-game press conference that Waerea-Hargreaves has suffered a pectoral injury - although not as bad as feared without a full rupture - and Manu has suffered an ankle injury.

"Joey [Manu] has an ankle and Jared [Waerea-Hargreaves] has a pec, so how bad I'm not sure, but obviously couldn't come back on the field," Robinson said.

"I don't know. I don't think it was ruptured [Waerea-Hargreaves' pec]."

Reports came during the earlier game in the evening between the Canterbury Bulldogs and New Zealand Warriors that Walker had sustained a knee injury, with the severity still to be determined.

"For the Sydney Roosters, some breaking news. The young gun halfback Sam Walker who was dropped to NSW Cup recently has suffered a knee injury," sideline reporter James Hooper said on Fox Sports' broadcast.

"He did not play NSW Cup tonight. He may require surgery and he is out for a minimum of three weeks. He is in a knee brace currently."

Robinson squashed the idea that Walker may need surgery though, saying it would be a few weeks in a knee brace and a hopeful return after the Roosters' Round 13 bye.

The club only have one game left before that - against the St George Illawarra Dragons next Friday at Kogarah, before they take on the Canterbury Bulldogs in Round 14 at Gosford.

"It's not that bad," Robinson said on Walker.

"It's a couple of weeks in a brace, and then post-bye would be what I think when he is going to come back."

Ordinarily, an injury to Manu would have brought the dropped Walker straight back into first-grade, however, Drew Hutchison may now be the call up for the tri-colours.

Robinson said plans would be made during the week for the clash against the Dragons.

"There is no plan ten minutes after the game," Robinson said on how the Roosters' would replace Manu next week.

"We have enough players there to do what we need to do, but it's not about individuals, it's about us collectively as a whole crew getting it fixed pretty quickly and getting back to a Roosters' style of footy."

The club will likely confirm the extent of all three injuries in the coming days once scans are completed.