Ferguson has been linked with several A-League clubs, including Miller's Roar, but he told the Scotsman on Sunday: "Each club has a marquee player who you can pay a certain amount of money for.
"They'd have to put two clubs together to be able to afford Barry. If he wants to come, he would be more than welcome, but I don't think it is time yet. He still has a year left on his contract. He could turn out to be a golden boy again. I just hope Rangers don't throw him out too soon."