Manly could be forced to turn to Brendan Elliot to start the season at NRL fullback with Tom Trbojevic in serious doubt for round one due to a hamstring injury.
The Sea Eagles fear Trbojevic could be out for a month after he pulled up sore when returning a kick in the club's trial loss to Cronulla, forcing him to leave the game at Shark Park and not return.
The NSW Origin ace was expected to go for scans as soon as Sunday, with the Sea Eagles sweating on the results before their March 16 clash with the Wests Tigers.
If Manly's marquee man is ruled out, 25-year-old recruit Elliot will likely to be moved to fullback, after he assumed the role from the departed Trbojevic on Saturday night.
Elliot has played 40 matches in a stop-start NRL career since he debuted in 2014 and spent just seven of those games in the No.1 jersey for Newcastle in 2017.
He played just three games for the Gold Coast last year before he linked up with the Sea Eagles over the summer.
It could also represent one of several issues for Des Hasler's backline.
Outside backs Brian Kelly, Akuila Uate and Matthew Wright were all released after the 2018 campaign while star centre Dylan Walker's future could likely be decided this week.
Walker will face Manly Local Court for a hearing before a magistrate on domestic violence charges, which he pleaded not guilty to in December.
The ARL Commission will meet this week to decide a policy on standing players down while serious matters are still before the courts.
Manly had rookie Reuben Garrick on one wing against the Sharks, with Jorge Taufua on the other.
Walker and Brad Parker played in the centres.
Teenager Albert Hopoate could also figure come round one, as he returns from an anterior cruciate ligament injury.
The versatile back turns 18 on Monday and will be eligible to face the Sydney Roosters next week.
"He's in our top-30 squad, so anyone who is involved in that is a genuine chance," Manly captain Daly Cherry-Evans said of Hopoate.
"He's trained the house down and is going really well. He's just got back from the contact phase of his knee injury.
"I hope his story is a successful one and I'm excited to hopefully play alongside him this year at some stage."
Australian Associated Press