Lussick heard a worrying crack in his ankle after taking the first hit up in Saturday's trial loss to Cronulla.

Limping around with a moonboot on his right leg on Monday, the prop said he had been diagnosed with a high ankle sprain and would be out for four to six weeks.

"I was fearing the worst," Lussick said.

"I've never had a problem with my ankle and one of their big fellas came down and fell on it. There was nothing I could do."

Lussick had sent social media into a spin when he sent a message that he was giving away the boots he used in the trial match, with some interpreting it as him being ruled out for the season.

"I still am looking forward to a big 2018," Lussick said.

"Hopefully I'll only miss one game. I've had a pretty good pre-season - injury-free until this point."

Heading into their March 9 season opener against Newcastle, coach Trent Barrett also has injury concerns over centre Dylan Walker.

Walker was expected to miss the first four rounds after undergoing five operations over the off-season.

After having his ankle, which he dislocated during the Prime Minister's XIII game, operated on twice, he underwent a shoulder reconstruction which had previously been booked in.

He also had to have two operations to remove a stone in his salivary glands.

While he is back running with teammates, he said could not put a firm date on his return.

"We've spoken to the doctors and medical staff at Manly and it's just one of those ones where they can't put a time on it," Walker said.

"Just because of how I'm running and until my confidence comes back. It's supposed to be round four but it depends on how I'm feeling because I don't want to go back into it not feeling confident.

"I'd just let the team down more than anyone else."

Australian Associated Press