But the player has rejected a move to North Lincolnshire, according to Warnock.
He said: "Billy has turned down the offer, and we have told him he doesn't have to go.
"We are in the process of offering him a new contract, and if he signs we will let him go out on loan.
"I thought Scunthorpe would be a good move for him, playing at that level, and £100,000 was a realistic offer for Billy."