St Helens goalkicking scrum-half Luke Walsh has been ruled out for up to six weeks with a calf injury.
Australian Walsh, who was injured in Saints' 40-22 win over Catalan Dragons last Friday, has made a big impact in First Utility Super League, scoring 64 points in his opening five matches and playing a key role in Saints' 100 per cent start.
Saints captain Paul Wellens believes his side will cope without Walsh, with the versatile Jon Wilkin able to slot back into the crucial half-back role.
"You always want your better players playing for you, that goes without saying, but I think we're fortunate in the fact that at the back end of last year we were playing without a half-back," Wellens said.
"Jon Wilkin filled in for that role and did a really admirable job so Wilko can come in and play that position, albeit it alters the way we play slightly. We should still remain competitive."
Saints will also be without centre Jordan Turner for Sunday's trip to Wakefield Trinity Wildcats after he damaged a hamstring against the Dragons and they have doubts over second rower Sia Soliola and prop Alex Walmsley.