He returned to Pompey and had a number of other loans away from Fratton Park before being released two years ago.
He signed a two year deal with Exeter and has finally got regular first team football with the Grecians. He's played in no less than 93 games for them during which he's scored four goals and picked up a total of 19 yellow and 2 red cards.
Manager Paul Tisdale was keen to keep him but it looked as though he might move on. However, Exeter have confirmed that he has signed the new deal and Duffy said: "Staying at Exeter was the best option for me and the club. I believe they can take my career forward.
"I had a bit of interest but I had a chat with my family and agent and decided that this was the club I wanted to be at. You want to be playing football but you want to be enjoying it as well. You want to like where you are living and the people you are playing with. All of that's important.
"I know the people in Exeter. I have been at the club for two years and I have enjoyed it, so another season will be good for me and the club hopefully."