The 28-year-old's only appearance for the Vikings this season came in the Challenge Cup win over Rochdale.
Coach Daryl Powell said: "Paddy comes to us at a crucial period.
"Whenever he has played against us he has had a strong influence on the game, he is a tough defender and carries the ball very strongly in all areas of the field."
Castleford Tigers have signed Widnes Vikings winger Paddy Flynn on loan until the end of the season.