Melbourne Storm duo Ryan Papenhuyzen and Reimis Smith have both been ruled out for a prolonged period, with the club confirming their injuriesonTuesday.

Papenhuyzen will be dealing with two injuries at the same time, having suffered a PCL injury during the first half against the St George Illawarra Dragons on Sunday.

He was able to play on through the injury initially, but was taken from the field during the second half after injuring his hamstring while scoring a second try during the 50th minute of the game.

The club have confirmed it's a hamstring tear for Papenhuyzen, who will be ruled out for at least four, but potentially as many as six, weeks.

Reimis Smith, on the other hand, has had scans returned to confirm he has suffered a ruptured pectoral muscle.

The club confirmed Smith is having surgery this week to repair the injury, and will miss anywhere between ten and twelve weeks, ruling him out until just weeks before finals.

Papenhuyzen is now unlikely to be fit for State of Origin 1, which is just over four weeks away and will be played on June 8.

It was thought he was strongly in contention for a spot on the Blues bench wearing the number 14 jersey, however Nicho Hynes now looks the favourite for that role.

Craig Bellamy hasn't revealed who will replace the star fullback yet, however it's believed Tyran Wishart is a chance while Nick Meaney could also shift to the back.

The Storm have also revealed they have received approval for development squad member Marion Seve to play in light of their backline injury toll.