Goalkeeper coach Jimmy Walker has left Sunderland to join Paul Lambert's backroom staff at Ipswich Town.
Walker, who was appointed by Jack Ross in the summer, has made the decision to be closer to his family.
He said: "It was a very difficult decision for me, as I have loved every minute at Sunderland and it’s a fantastic club.
“Being away from my family in recent months has been challenging so I would like to thank everyone at the club, especially the manager and staff, for their understanding.
“I wish the club and the fans every success for the rest of the season.”
Jack Ross said that Walker left with the club's 'very best wishes'.
"We are sad to see Jimmy go but understand his reasons," he said.
"He leaves with our very best wishes for the future."
Walker played for Lambert while the former Celtic midfielder was in charge at Colchester United.