Manly winger Jason Saab will miss six weeks with the hamstring injury he suffered during Manly's defeat of South Sydney in Las Vegas.
It comes as injury plagued second-rower Josh Schuster prepares to return from a calf strain in the NSW Cup this weekend.
New recruit Tommy Talau replaces Saab on the wing to face the Sydney Roosters this Sunday, with coach Anthony Seibold opting against moving Reuben Garrick from the centres.
Saab pulled up sore in the final five minutes at Allegiant Stadium in what was the only sour note of a 36-24 round-one win over South Sydney on March 3 (AEDT).
Scans have since diagnosed Saab with a high-grade right hamstring injury that is set to keep him sidelined until late April.
Ex-Wests Tigers speedster Talau now has the chance for an extended run in the starting side but Ray Vaega is another option to fill in.
Karl Lawton tweaked his ankle in the defeat of South Sydney but has been named on the bench to face the Roosters.
On return from a calf issue, Schuster will line up for Manly's feeder side Blacktown Workers in their NSW Cup clash with the Roosters on Sunday.
The second-rower missed the Las Vegas clash with the training injury, which came after he battled a broken finger and a bout of chickenpox over the off-season.
Second-rower Ben Trbojevic played a starring role in the Sea Eagles' defeat of South Sydney - another possible setback to Schuster's hopes of returning to the starting side.