If they can recast Bruce Banner, they can recast Doc Samson. They could explain his powers in show. Maybe have him come in as some kind of consultant for Talbot, have a Gamma accident (maybe something vaguely like a device to fight inhumans or something that is powered by gamma radiation and becomes unstable) and there you go. He'd be a good super ally for Talbot, and anew powered psychiatrist could be interesting on the show. I really can't see them doing it (I doubt they'll ever use Samson, and if they did it would probably be a Hulk related scene in Avengers), but it would be pretty easy to do.