Star Sharks prop Aaron Woods could miss up to three months with a fracture in his foot.
The 28-year-old will undergo surgery to repair the Jones fracture he sustained in his side's 24-12 loss to Parramatta on Saturday.
His timeline for recovery is believed to be between 10 and 12 weeks.
Woods is the latest key Shark to go down, with injury concerns hovering over the likes of Wade Graham, Matt Moylan, Paul Gallen and Shaun Johnson.
Meanwhile, Manly is likely to be without the services of star fullback Tom Trbojevic for an extended period of time as he deals with his latest hamstring setback.
The strain is believed to be a recurrence of an injury suffered during the pre-season and is expected to keep the 22-year-old sidelined for between six and nine weeks.
The Sea Eagles will travel to Newcastle to take on the Knights on Saturday evening, while the Sharks host the Roosters on Saturday night.