The Manly Sea Eagles could be without three star forwards for Round 1, with Haumole Olokau'atu being the second player to pick up an injury during their second and final trial match with the Canberra Raiders.

Olokau'atu's second row partner, Josh Schuster, is already set to miss the opening weeks of the season with an injury sustained during pre-season training.

Martin Taupau's return to action then lasted less than 100 seconds though as he was folded awkwardly attempting to make a tackle under the weight of Raiders young gun Xavier Savage.

With half an hour to go in the second half though, Olokau'atu reeled awkwardly out of a tackle with the Raiders on the attack, his elbow appearing to hyper extend as he hit the ground in a worrying-looking arm injury.

The star second rower, who had a breakout season in 2021, then was taken from the field by trainers, with the Sea Eagles set to wait for scans, but suspecting he has a fractured forearm.

Fox League's sideline commentator Jake Duke said the injury was worse than commentator Corey Parker had been suspecting in the commentary box.

"It's an arm injury, but it's worse. It's a suspected fractured forearm for Olokau'atu," Duke said.

"Obviously scans and X-rays will be needed to confirm that injury."

It came after the Sea Eagles medical staff earlier revealed that Martin Taupau would be "touch and go" for Round 1, with a jarred back the result from the tackle he had been folded awkwardly in.

A fractured forearm for Olokau'atu could leave him missing the opening weeks of the season, with Manly's first clash of the year less than a fortnight away against the Penrith Panthers on Thursday, March 10.