Updated September 20, 2018 18:14:51

Photo: Paul Gallen is a late scratching from the Sharks' line-up to face the Storm. (AAP: Craig Golding, File)

Cronulla captain Paul Gallen has been ruled out of Friday night's preliminary final against Melbourne after failing to recover from a shoulder injury.

Gallen sustained the injury in the 21-20 win over Penrith in last week's semi-final and the Sharks had intended to give the 37-year-old up until just before kick off in Melbourne to prove his fitness.

He travelled with the squad to Melbourne on Thursday but after receiving treatment from the Sharks' medical staff he was ruled out of the sudden-death encounter with the Storm.

The Sharks had been told Gallen could not aggravate the shoulder injury but the decision was made to leave him out of Friday night's match.

They are "optimistic" Gallen will be available should the club beat the Storm and advance to the grand final on September 30.

Sharks coach Shane Flanagan had admitted earlier on Thursday Gallen was "against the odds" of being passed fit to play the Storm.

He said Gallen, who had trained with the Sharks in Sydney on Thursday, would likely have played if the preliminary final was not scheduled for Friday night.

"If it was a Sunday game I would say he'd be in," Flanagan said.

The Sharks had already been hit by injury during the finals series, with back rower Wade Graham sidelined until next year after tearing his ACL against the Sydney Roosters in the opening week of the play-offs.

Luke Lewis is expected to be named Sharks captain in Gallen's absence.

Topics: sport, rugby-league, nrl, cronulla-2230, melbourne-3000

First posted September 20, 2018 17:56:30