Shaw is now focused on finding a successor and admits the highly-rated Ferguson - currently a free agent after leaving Peterborough in November - is on his radar.
Shaw told Sky Sports News: "Darren Ferguson has excellent credentials and we would be silly not to want to see him.
"We have spoken to representatives of a couple of the other (targets) and we want to get this decision right and we want it sooner rather than later."
Shaw also admitted one of his targets had ruled himself out, adding: "There's nothing we can do about that. But we want to get our managerial situation sorted out as soon as we possibly can and I can assure the supporters we are doing everything in our power to do that."