The Northern Ireland international is on trial at London Road and, after he set up the only goal in their pre-season victory over Northampton, Ferguson spoke of his desire to sign the former Celtic man.
"I've known of Paddy for years and we tried to sign him when he moved to Celtic a few years ago," he told the Peterborough Telegraph.
"He is a very good player who has outstanding ability on the ball and great balance. He can play in a number of different positions.
"We'll talk again...and see where it takes us. He has other offers but he has made it clear he wants to come here."