The NSW star picked up the injury in his left ankle in the first half of Saturday's victory over Brisbane and is expected to be out for six weeks.

It means the earliest he can return is the first week of the finals.

Utility Tyrone May has also suffered an MCL injury and is sidelined indefinitely, adding to the long list of outs for the second-placed side.

Nathan Cleary's recovery from a shoulder injury is positive, but the star halfback has not been named to face Melbourne in the top-of-the-table clash on Saturday night.

Co-captain Isaah Yeo (concussion), Apisai Koroisau (suspension) and James Fisher-Harris (personal leave) are also missing from the team to take on the Storm, leaving fullback Dylan Edwards to captain the inexperienced side.

The injuries come at a terrible time for Penrith ahead of the grand final rematch in which the Storm are chasing their 16th straight win.

Origin stars Cameron Munster, Felise Kaufusi and Dale Finucane are set to return after being rested last week, while Harry Grant has been named on an extended bench.

The Sydney Roosters have also been hit with a spate of injuries in the outside backs with confirmation Matt Ikuvalu (ankle) and Billy Smith (foot) will both undergo surgery.

Smith was just three games into a return from a shoulder reconstruction and ACL injury before suffering a fractured foot against Newcastle on Friday.

Teenager Joseph Suaalii was ruled out for the season earlier this month with the same injury.

"It's just moved around (Smith's) body in the last couple of years which has been disappointing for him and us as a team," said coach Trent Robinson on Tuesday.

"It's through no fault of his, he's just a young guy and his body is learning to adapt to NRL but also just some ligament issues there that we want to dig a bit deeper into, we want to help him.

"He's got a big future, we're just going to have to repair this foot and go again."

After being dropped last week for Smith, Josh Morris has been named to make his return in the centres against Parramatta on Thursday night.

Adam Keighran has been named on the opposite edge with Joseph Manu moving to the wing.

"We're starting to get thin there as a crew, but there's no excuses there," Robinson said.

"There's belief in the way we play and the 17 that will play will be ready to go.

"It's obviously been disappointing that within four weeks we've lost three outside backs.

"It's a bit of our year at the moment, that's the way it's been, but spirits are high."

Australian Associated Press