Castleford will be without forwards Mike McMeeken and Matt Cook for Thursday's Betfred Super League round two game at Hull.
England second rower McMeeken is a victim of the seven-day rule after suffering a concussion in the first minute of the Tiger's opening 20-4 win over Catalans Dragons last Friday while Cook also took a knock in that game.
Forward Mitch Clark and utility back Ben Roberts, who were left out of coach Daryl Powell's initial 19-man squad last Friday, are set to plug the gaps, although youngsters Tuoyo Egodo and Jacques O'Neill have also been called up.
Powell said: "There's a couple of changes in there, but we're not far off. I thought Alex Foster did a great job in the back row when he came on for Mike so he will take that role again.
"The bench will change a little bit. We've got Mitch Clark to come in and Ben Roberts is fit and available so I'll make a call on the bench."
Hull are boosted by the return of England international Jake Connor and former Castleford forward Joe Westerman as they look to halt a 12-match losing run going back to June.
Connor missed Friday's opening 18-16 defeat at Hull KR through suspension while Westerman has recovered from a knee injury and is set to take the place of Dean Hadley, who has an abdominal problem.
