Barnsley manager Keith Hill admits he is resigned to losing Jason Shackell this summer after the defender's agent made it clear he wants to leave.
Shackell, who has two years remaining on his contract at Oakwell, has been heavily linked with a move to Championship rivals Derby.
Hill claims nothing has yet been decided, but expects the 27-year-old to call time on his Tykes career.
"Nothing is concluded yet, but I am resigned to losing Jason," he told Barnsley's official website.
"I've spoken to his representative and he has made it very clear that Jason Shackell wants to leave Barnsley.
"From my point of view and the club we want to get this sorted out as quickly as possible so we can see where we move from there in formulating a squad of players for the start of the season.
"I believe he is an excellent player who will be missed, but my job, as the manager, is to replace him as quickly as I can and move forward.
"If he does end up moving away I may have more options in the transfer market as a result of that. What we do need are players who want to play for Barnsley Football Club."
Young Derby defender Miles Addison has been linked with a move the other way, and Hill has confirmed his interest in the 22-year-old.
"Miles is a player I admire and there is a possibility of him coming from Derby County," he said.
"I know him well and he is someone I would like to see come here. I believe he would be a great acquisition for Barnsley Football Club."
He added: "I'm still looking at our squad and I am trying to get a well balanced side.
"It's not going to be a big squad, but one that will have quality and ability. I am still looking to bring around five or six players to add to the current squad."