Marika Koroibete scores for the Storm against the Warriors at Aami Park in Round 5.

Melbourne has been dealt a significant blow ahead of Saturday night's clash against Penrith with leading try scorer Marika Koroibete set to miss the next six weeks with a fractured thumb.

The Fijian suffered the injury in the 70th minute of the Storm's 24-2 blowout loss at the hands of the Roosters on Monday night.

Scans on Monday confirmed the extent of the damage that will see Koroibete miss his first string of games since making his Storm debut in Round 18 last year.

The 22-year-old has set the competition alight with some scintillating highlights this season.

His seven tries in 11 games make him the club's joint-leading try scorer alongside Will Chambers.

Koroibete also ranks equal fourth in the NRL for total line breaks (8) and second for total metres.

As far as replacements go Young Tonumaipea is the obvious choice, though he has not played since Round 4 when he lost his spot in the backline to fellow Victorian Mahe Fonua.

Despite making way for the returning Billy Slater when the teams were announced on Tuesday, Cameron Munster could earn a surprise recall.

Munster has been spending significant time on the wing at Queensland Cup level as the Storm look for another place to fit the 20-year-old in their side. The prodigious talent has shown enourmous promise in the four games he has filled in for Slater this season.

Koroibete's injury is another unwanted hurdle for the Storm who are already trying to overcome a five-day turnaround and back-to-back road trips. 

They have remained in NSW for the week as they attempt to right the ship following their worst lost of the season on Monday night.