Melbourne forward Joe Stimson is in doubt for the Storm's NRL season opener against Brisbane with a lower-back injury.
Melbourne didn't name Stimson in a provisional 21-man squad by at a Sunday fan day, after missing the Storm's last pre-season trial against North Queensland.
Sunday's extended squad is not the Storm's official entry for the first team naming of the year, and might still change before Tuesday's deadline.
Stimson played all but three games last year for Melbourne, starting in the second row throughout the finals series ahead of retiring veteran Ryan Hoffman.
His injury is not considered a long-term threat.
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Fellow forward Tui Kamikamica has been named despite picking up a minor knee injury in the trial loss to the Cowboys.
Jahrome Hughes is also in the squad after not playing in either of the Storm's trials, now set to fill Billy Slater's old No.1 jersey with Scott Driinkwater ruled out for up to three months with a pectoral injury.
"Billy's shoes are massive to fill," halfback Brodie Croft said.
"But we've got high-calibre players in Jahrome Hughes - he's done a really good job.
"It's unfortunate for Scott Drinkwater. He had a really good pre-season.
"That competition for the fullback spot really got the best out of those two players."
STORM 21-MAN SQUAD (in alphabetical order):
Josh Addo-Carr, Nelson Asofa-Solomona, Jesse Bromwich, Kenny Bromwich, Will Chambers, Brodie Croft, Tom Eisenhuth, Dale Finucane, Jahrome Hughes, Tui Kamikamica, Felise Kaufusi, Patrick Kaufusi, Cameron Munster, Ryan Papenhuyzen, Curtis Scott, Marion Seve, Brandon Smith, Cameron Smith (capt), Suliasi Vunivalu, Billy Walters, Christian Welch.
