Sam Rockwell was considered for the role of Iron Man, but the part ultimately went to Robert Downey Jr. However, director Jon Favreau saw something in him, which is why they offered him a role in Iron Man 2 as the villain, Justin Hammer. And in a way, Sam still found a way to play Tony Stark…kind of.
“Jon had called me about possibly screen-testing for the part of Tony Stark in Iron Man,” Sam Rockwell told The A.V. Club. “And whatever happened, I think I was out of the running. Robert just killed it, you know, and I never heard anything after that. We gave Justin Hammer the glasses and kind of sleazed him up a little. It was a chance to do Tony Stark.”