How Bradley Cooper And Christian Bale Almost Swapped 'American Hustle' Roles

It could have been Cooper gaining 50 lbs. and rocking a combover in the new David O. Russell movie.

Wherever director David O. Russell goes, unpredictability is sure to follow.

The filmmaker, most recently known for the upcoming "American Hustle" and the Academy Award-nominated "The Fighter" and "Silver Linings Playbook," loves working with the same actors and actresses repeatedly (Christian Bale and Amy Adams were front and center in "The Fighter" and Bradley Cooper and Jennifer Lawrence duetted on "Silver Linings Playbook"), but that doesn't mean he doesn't have tricks up his sleeve.

Bale will go down in history for his turn as Irving Rosenfeld, the paunchy conman, and Cooper has earned his own accolades for his portrayal of Richie DiMaso, the FBI agent who spearheads the sting operation central to the movie's plot. The two embody their roles so perfectly that it's hard to imagine anyone else. However, the cast revealed to MTV News, Cooper nearly played Bale's part.

Russell's first thought for the role was Bale, but the "Dark Knight Rises" actor was unavailable to shoot.

"Christian was gonna do it, then he couldn't do it, so I was gonna swap over and play Irving, and Jeremy [Renner] was gonna play the FBI agent, and then Christian came back available and we slid back," Cooper revealed. The shift in casting opened up a whole new role for Renner, who eventually ended up as Carmine Polito, a crooked New Jersey politician.

Russell said that the kinetic nature of the way he makes his movies — including recasting, improvisation and experimental plot changes — is borne of love of his actors and their abilities.

"I want to see them do stuff that I love as a moviegoer, that's why I'm there," he said. "I don't want to go home and go 'oh, shoot.'"

"American Hustle" hits theaters December 20.