I don't think Duff is going to make it. He's got an injured rotator cuff, so he can't do anything to improve his standing. Do you keep a guy who's injured, and inexperienced? Maybe practice squad. And from what I've heard in practice, he's been beaten badly a couple of times.
Also, his last season at Notre Dame wasn't as good as his previous ones. Think Starling and Moses both have him beat right now.
Can't afford a signature