St Helens forward Sia Soliola faces up to 10 weeks on the sidelines as he undergoes surgery on a foot injury.
The 26-year-old New Zealander suffered the injury playing for the Exiles in the 30-10 defeat by England.
Soliola, who joined Saints from Sydney Roosters, has been a regular in head coach Nathan Brown's side this season having missed just one match.
"The upside is that it gives another player the chance to step up and stake a claim for a place," Brown said.
"Our squad as a whole has gained vital experience throughout the course of the year and I have no doubt we will adapt and continue to develop."
Joe Greenwood comes into the squad for Friday's game at Salford as a replacement, while prop Anthony Laffranchi returns from injury.