St Helens are set to give a Super League debut to former Batley forward Alex Walmsley against Hull on Friday night.
The 22-year-old 6ft 5in prop has been drafted into coach Nathan Brown's 19-man squad as a replacement for Australian front-rower Josh Perry, who will be out for a month with a knee injury sustained in Sunday's 14-4 win at Widnes.
Walmsley was one of Brown's three close-season signings and played in Saints' pre-season trials, but spent the first two weeks of the season on a dual registration with his old club Batley.
"Big Alex is more than likely to come in for Josh," Brown said. "He has done well. His form in the friendlies has been good and his attitude is first class."
Saints will also be without utility player Lance Hohaia for a month after he damaged a shoulder at Widnes, but are hopeful hooker James Roby will return after missing the round-two game with a foot injury.
Hull FC coach Peter Gentle has retained the same squad that was on duty for the 28-12 win over Bradford last Sunday.
Forwards Danny Tickle and Liam Watts again miss out through injury.
St Helens squad: Wellens, Gardner, Turner, Soliola, Meli, Lomax, Roby, McCarthy-Scarsbrook, Puletua, Wilkin, Manu, Laffranchi, Flanagan, Jones, Gaskell, Makinson, Greenwood, Walmsley, Walker
Hull FC squad: Arundel, Briscoe, Crooks, Crookes, Galea, Green, Heremaia, Holdsworth, Horne, Houghton, Johnson, Lynch, McDonnell, O'Meley, Pitts, Seymour, Westerman, Whiting, Yeaman