Hill said: "It depends on the type of bids we receive, but as far as I'm concerned he's contracted to this club until at least the end of the season.
"He's contractually obligated to stay with us if we don't like or don't accept any fee."
Hill added: "If he did go he would be replaceable, there's no question about that. It might not be like for like. It's very difficult to find a Jacob Butterfield.
"But there'll definitely be a replacement. The replacement might already be in the squad."