Now this is just a rumor, but I'm going to throw out the big giant spoiler warning sign just in case.
The rumor is that a new Hulk may be making an appearance in Civil War. Since Avengers: Age Of Ultron ended with Bruce Banner flying off to be alone… it would take something might powerful to pull him back. And the rumor says that what gets him to return is the Red Hulk. Now in the comics, the Red Hulk is General Thunderbolt Ross… and it just so happens that William Hurt will be reprising his role as Ross in the film. And there is supposed to be a fight between the two Hulks to rival the fight between Hulk and Hulkbuster Iron Man.
So will we get a Red Hulk in Civil War? Sounds cool to me.