 Rockwell was interested, but Favreau changed his decision after the screen-test of Robert Downey, Jr. (Rockwell would later portray Justin Hammer in "Iron Man 2" (2010)).In September 2006, Robert Downey, Jr. was cast in the role.Favreau chose Downey, a fan of the comic, because he felt the actor's past made him an appropriate choice for the part, explaining "The best and worst moments of Robert's life have been in the public eye.