Wellens' absence means Tommy Makinson is poised to start at full-back while Josh Jones will make his home debut after his first appearance at Warrington.
Prop forward Tony Puletua is back from injury but Gary Wheeler has been left out as he continues to recover from a knock picked up against Leeds.
Wigan are expected to call upon prop Gil Dudson for his debut and threequarter Anthony Gelling for his second start with Lee Mossop, Ben Flower and Liam Farrell (hip) ruled out.
Epalahame Lauaki misses the short trip as he serves the second of his two game suspension.
St Helens squad: Wellens, Gardner, Shenton, Soliola, Meli, Hohaia, Lomax, Perry, Roby, McCarthy-Scarsbrook, Puletua, Wilkin, Flannery, Flanagan, Clough, Magennis, Dixon, Makinson, J. Jones.
Wigan squad: S. Tomkins, Charnley, Goulding, Carmont, Richards, Finch, Leuluai, Prescott, McIlorum, Hansen, Hock, Lima, Tuson, Dudson, Gelling, Mellor, Hughes, Spencer, L. Tomkins.