Melbourne are hopeful strike centre Jack Howarth will not need a shoulder operation as their outside back injury setbacks continue.
The 22-year-old dislocated a shoulder in the dismal 42-22 loss to the Dolphins on Friday night.
Howarth is considered to be a future long-term Queensland player in the State of Origin arena.
His injury came on the back of coach Craig Bellamy confirming pre-match that Storm captain and Queensland and Australia hooker Harry Grant would miss four to six weeks with a hamstring injury, sustained in Thursday's captain's run.
The outside backs are the area where the Storm are now thin on the ground.
Winger Dean Ieremia ruptured an Achilles in pre-season and is not expected back until late June.
Bellamy said he was unsure if winger Will Warbrick (concussion) would be fit to play South Sydney on Friday night and added that versatile centre Nick Meaney (broken jaw) was "probably a couple of weeks away".
"We are just running out of centres," he said.
"Moses Leo last week had a shoulder operation and he is going to be out for three months."
Howarth's injury has added to the casualty ward after he came off in the 17th minute against the Dolphins.
"He will be (out for) an extended time but if he has an operation it will be the season I think," Bellamy said.
"I think he will try and rehab it and go from there. I don't think it was out for too long so that is a plus, but we will see what the medical team think.
"They are thinking to rehab it and try him again.
"Jack has been in really good form the last couple of weeks and made improvements in his game. He was looking likely out there tonight too but unfortunately that is a bad injury for him."
Melbourne led 16-2 after 20 minutes before being blown off the park.
The Storm are famous for gritty wins where defence is paramount. Last year's 8-0 victory over Penrith in round one was a classic example. This year they are yet to win a tight game on the back of defensive resolve.
"It seems to be a bit like that," Bellamy said.
"It is a big concern to just rely on your attack. We have been aware that our defence hasn't been as good as we'd like it to be.
"I'll have to look through it to see where the problems are … and see where we can improve next week."
Bellamy said there may have been complacency after leading 16-2 when his team "put slippers on" thinking they had put the game to bed.
"I'd hate to think that happened," he said.
"We will do our review and need our players coming in, not with excuses, but reasons why what happened might have happened."
