"We've had bids from Leicester and Bolton for Mark," McCarthy told the club's official website.
"We actually want to keep him and have offered him a new deal but he doesn't want to stay and has put in a transfer request.
"So if there's a deal that can be done that is right it could happen.
"I don't know what has happened with the bids as I don't deal with that side of things but I imagine negotiations will be taking place."