Wigan have revealed that the 29-year-old expressed a desire to leave the club and refused to take part in pre-season training after Christmas.
Chairman Ian Lenagan told the club's official website: "Gareth Hock has made it clear in face-to-face discussions with me and via his agent that he has no intention of playing for the Wigan club. This is hugely disappointing to me, to the Wigan fans and to the club who have all treated him well.
"A line has to be drawn at some stage and whilst with immense regret at losing a player of Gareth's quality, who I believe is still a Wiganer at heart, we have concluded that that time is now for the good of the 2013 Wigan squad, the coaching staff and for the Wigan fans. Having stood by Gareth Hock, we feel let down by his attitude."
Hock came through Wigan's academy.