In addition to Vin Diesel, a couple other actors have also been rumored to be in the film such as Steve Agee, Stephen Blakehart, and Sean Gunn. When questioned about why certain names weren’t yet listed on IMDB, director James Gunn clarified a couple casting rumors involving supporting roles.
“IMDB is not always correct. Even right now I believe it contains misinformation. A complete cast list will not be released until closer before release- and we are not currently releasing a list of all the characters in the film,” answered Gunn. “That said, Stephen Blackehart and my brother Sean are in the film but my good friend Steve Agee is unfortunately not. Although he would make a great Thanos (not really).”
In fact, despite the rumors, Steve Agee did not even audition for the film. Gunn revealed, “Besides my brother and Gregg Henry, and a couple of others, we pretty much cast all of the supporting roles out of England. There's a lot of take there, so it wasn't hard! I love working with Steve, though - he's a great friend and an incredibly funny guy.”
Guardians Of The Galaxy is scheduled to be released in movie theaters on August 1, 2014.