Ade Gardner (knee) and Tony Puletua (shoulder) are omitted and it is still too early to state how long they will be out for.
Gary Wheeler and Tommy Makinson (both hamstring) are set to return in two to three weeks and Jon Wilkin is progressing well from the shoulder injury he sustained in the match against Wigan on Good Friday.
Dennis Betts says "You need a bit of luck in the draw and you need to play particularly well in knock out rugby but there's always that opportunity. You're just three or four games away from something very, very special."
Having played for one club with a great Challenge Cup tradition he now coaches another, Widnes, who were known as the "Cup Kings" in the 1970s. "Being involved with a club who have a great tradition with the cup generates a buzz and you can feel that at Widnes. It will be a great spectacle on the weekend when we play another side who have had so much success in the Challenge Cup in a different era."
Widnes have not beaten St Helens in the Challenge Cup since winning the 1930 Final at Wembley.
The Saints have won the last five Cup meetings between the sides since then.
Widnes 19-Man squad: Patrick Ah Van, Hep Cahill, Jon Clarke, Danny Craven, Ben Cross, Chris Dean, Paddy Flynn, Alex Gerrard, Kurt Haggerty, Rhys Hanbury, Declan Hulme, Willie Isa, John Kite, Macgraff Leuluai, Anthony Mullally, Jack Owens, Steve Pickersgill, Lloyd White and Frank Winterstein.
St Helens Squad: 1. Paul Wellens, 3. Michael Shenton, 4. Sia Soliola, 5. Francis Meli, 6. Lance Hohaia, 7. Jonny Lomax, 8. Josh Perry, 9. James Roby, 10. Louie McCarthy-Scarsbrook, 13. Chris Flannery, 14. Anthony Laffranchi, 15. Mark Flanagan, 16. Paul Clough, 18. Shaun Magennis, 19. Andrew Dixon, 22. Jamie Foster, 26. Josh Jones, 28. Joe Greenwood, 34. Adam Swift.