Melbourne chief executive Justin Rodski says they want to recruit another outside back after losing Ryan Papenhuyzen to a season-ending injury.

Ryan Papenhuyzen's kneecap was shattered into 10 separate pieces according to Melbourne chief executive Justin Rodski, who says the NRL club will now head to the market for a replacement.

Papenhuyzen's season ended when he was trampled by Canberra's Jack Wighton on Sunday.

He was immediately taken from the field in excruciating pain and has successfully undergone surgery.

The flying fullback joins Xavier Coates, George Jennings and Reimis Smith on Craig Bellamy's long-term injury list.

"He broke his kneecap in, I think, 10 places so it was a pretty brutal injury," Rodski told SEN.

"His recovery time is somewhere around three months so we won't see him again this year unfortunately.

"They have put pins and clips that stay inside your knee and it can heal really quickly."

The Raiders condemned the Storm to a third consecutive defeat for the first time since 2015, leaving Melbourne fighting for a top-four spot.

The Storm face a resurgent South Sydney this weekend and have opted to name utility Tyran Wishart on the wing with Nick Meaney slotting in at fullback.

With such a big list of injuries, Rodski hoped the Storm would be able to bring in an extra body prior to the NRL's August 1 signing deadline.

"We'll be stretched in terms of our depth," he said.

"We've got one more list spot to fill and we are working through our options.

"An outside back is key for us moving forward with Papenhuyzen now out.

"It's going to be a challenge but if anyone can do it, it's Craig Bellamy."