"Nothing more has happened with regards to any potential move to Birmingham , but one or two other clubs are keen on David," Williams told the Lancashire Evening Telegraph.
"We have reached a position where we have told City what we are prepared to accept, despite being reluctant sellers.
"We don't want to lose him, but equally you don't want to stand in a player's way when he wants to leave.
"So far, we have been unable to reach any agreement and soon we may have to think about getting on with it and David coming back for pre-season training." 