Bradley Cooper wasn't sure if he was right for American Sniper.
The 39-year-old actor admitted as much in an interview with Deadline. Cooper will portray Chris Kyle, a real-life Navy SEAL and the most lethal sniper in American military history, in the new Clint Eastwood film, but initially thought a different star would be better suited to the part.
"I didn't really think I was right for him at all," he recalled. "I saw a photograph of [Kyle]...and I thought, I'm a buck-eighty-five. I'm from Philadelphia. You know what I mean? [Kyle was a] 230-pound, Odessa-born, beef-fed Texan...in my mind, I thought Chris Pratt would've been perfect."
"I had to basically change my complete body chemistry," he revealed. "I had to learn how to talk like him. I had to be pretty efficient with [weapons] and...carry all that weight ... To be able to do all that stuff without thinking about it took a tremendous amount of preparation."
In addition to other research, Cooper read Kyle's autobiography of the same name, and felt a strong and emotional connection to the soldier. The film was not yet in pre-production when Kyle was shot and killed by a fellow veteran, and the actor felt even more of an obligation to serve him well.
American Sniper will follow Kyle on his four tours of Iraq, and depict his troubled return home. Sienna Miller and Max Charles co-star as wife Taya and son Colton Kyle, with Luke Grimes and Kyle Gallner as Navy SEALs Marc and Winston.
American Sniper opens in theaters January 16, 2015. Cooper last appeared on film as Richie DiMaso in American Hustle, and will reunite with co-star Jennifer Lawrence in period drama Serena in 2015.