Dennis Wise wants a youthful number one goalkeeper and has told the former Chelsea player he would be third choice behind Graham Stack and Tony Warner if he remained at the club.
"I've told Sully that, whatever condition he's in, he's going to be third-choice goalkeeper," Wise said in the Yorkshire Evening Post.
"He should be looking to get a number one shirt and, if I'm being honest, I'm looking for a younger, more athletic goalkeeper.
"It's his choice, and he has to do it for himself. He can be a second here, and a really good second for me, or he can go and play in the lower divisions."