The official website gave the news today that Zivkovic, who signed on a three year deal during the summer, had left the club.
The Croatian international blamed poor trining facilities and being played out of position as reasons for his departure.
The unhappy player said: "My relationship with the manager has deteriorated in the past two to three months. I didn't feel like I was respected or wanted.
"He was always saying things were my fault in front of the other players in the dressing room. But he never said to me once that I played well.
"I feel my confidence has been totally ruined".