Moylan was on Friday ruled out of their sudden-death clash after failing in his bid to overcome a nagging hamstring injury that has plagued his season.

Morris suggested Moylan would likely return should the Sharks defeat the Sea Eagles and advance to a semi-final against South Sydney next week.

"He probably could have played, but (it was) just one of those things where he's not quite sure. There's an element of doubt there," Morris said.

"Just given his last few weeks with it trying to get it right we just didn't think it was right to risk him. So we go without him for this week.

"And hopefully the boys get the job done and we get some more footy out of him."

Dugan will again deputise in the No.1, where he has impressed since Moylan aggravated his hamstring issue three weeks ago.

Morris said playing Moylan meant coming up with contingencies in his backline in case the one-time Kangaroos representative suffered another setback.

"Given it's a hamstring and given he's in a key position, if it goes wrong you haven't got a lot of cover," Morris said.

"We want to put the team first and hopefully he can get himself right and we can get the job done so he can get at least one more game.

"(Dugan has) performed real well (at fullback) this year. It allows us to continue with the same spine we've had for the last few weeks.

"For me, it's about building on last week's performance.

"And Duges did a really good job there. He's working really well with Shaun (Johnson) and Chad (Townsend) so we look forward to continuing that."

Winger Aaron Gray will play just his sixth game of the season - and the first finals match of his career - in place of the suspended Ronaldo Mulitano.

Morris revealed Gray underwent knee surgery less than two months ago.

"So he's just been recovering from that, but he was strong for Newtown (in reserve grade) last week," Morris said.

"And if you just look at his games this year, he's played 5-6 games, and he was really solid for us and we've had wins in most of those games."

Australian Associated Press