SAINTS welcome back Mark Percival and Alex Walmsley for Saturday's Ladbrokes Challenge Cup tie at Castleford Tigers.

Matty Fleming and Adam Walker drop out from last week's squad.

Jon Wilkin is included after pulling up in warm-up last week.

Saints: 2. Tommy Makinson, 3. Ryan Morgan, 4. Mark Percival, 5. Adam Swift, 6. Theo Fages, 7. Matty Smith, 8. Alex Walmsley, 9. James Roby, 10. Kyle Amor, 12. Jon Wilkin, 13. Louie McCarthy-Scarsbrook, 14. Luke Douglas, 16. Luke Thompson, 17. Tommy Lee, 18. Dominique Peyroux, 19. Greg Richards, 20. Morgan Knowles, 28. Regan Grace, 36. Zeb Taia.

Castleford: 1. Zak Hardaker, 2. Greg Minikin, 3. Jake Webster, 4. Michael Shenton, 5. Greg Eden, 6. Rangi Chase, 7. Luke Gale, 8. Andy Lynch, 9. Paul McShane, 10. Grant Millington, 12. Mike McMeeken, 13. Adam Milner, 14. Nathan Massey, 15. Jesse Sene-Lefao, 16. Ben Roberts, 17. Junior Moors, 18. Matt Cook, 19. Gadwin Springer, 34. Alex Foster.