Melbourne will wait on scans on star five-eighth Cameron Munster's shoulder as they count the cost of wrapping up their third NRL minor premiership in four years.
Munster left the field late in the Storm's 36-6 flogging of Manly, on a drama- filled Saturday evening which also likely ended Manly star Tom Trbojevic's season due to a pectoral injury.
The news on Munster is not expected to be as bad.
He came into the Lottoland match with a shoulder complaint and was only cleared to play on Friday.
The Storm also have more freedom to play with, given they have wrapped up top spot and play North Queensland on Friday night at home.
"On Thursday, we thought he would be out. He had something in his neck or shoulder," Melbourne coach Craig Bellamy said.
"It's a bit different now - it's gone more into his shoulder. I don't think they know or want to say anything until they scan him.
"It's not too serious. He doesn't think it's linked to his neck but the physios seem to think it might be.
"We would like to be able to go in (against Cowboys) with the team we're going to go into the semi-finals with.
"But I think whatever happens, we probably will rest him next week."
Bellamy labelled the Storm's minor premiership his most special in his time at the club.
Melbourne have dropped just four games all year, with two of them in golden point.
It also comes after losing Cooper Cronk to the Sydney Roosters and Billy Slater to retirement over the past two seasons.
Sixteen of the 28 personnel they have used this year have been aged under 25, with only three to have played more than 150 games in their squad.
"I reckon this one is a little more special than the other ones we have won," Bellamy said.
"This is probably the youngest group Storm in my time here.
"I know there were some doomsayers at the start of the year who thought we might have dipped a bit.
"But some of those younger blokes have been outstanding this year. Not only have they been consistently good, they have got through some games.
"We've only been beaten four times this year and the biggest is four points. That's pretty consistent. And I'm quite proud of this group for that."