Chris Hemsworth Reacts to Kevin Costner Turning Him Down for a Film, Talks New 'Transformers' (Exclusive)

ET chatted with Hemsworth and Brian Tyree Henry about their upcoming animated film 'Transformers One,' premiering Sept. 13.

Chris Hemsworth is thinking about the role that got away.

On Thursday, ET chatted with the Australian actor and his Transformers One co-star Brian Tyree Henry after Paramount's studio presentation at CinemaCon, during which Hemsworth recalled a script for a Kevin Costner project that he didn't get.

"There was a movie, a script that I'd read and loved and was like, 'I want to get that,' and then someone said, 'Kevin Costner has that [role],'" Hemsworth told ET's Kevin Frazier. "I'd love [to have] him as a director. I was like, 'Goddamnit!' [I spent] an hour the other day trying to convince him and he was like, 'I'm doing it, kid.' Didn't work. I didn't get the part."

Hemsworth explained that the "abstract and interesting" film is "a small story about a man and a woman."

"It's better seen in his wheelhouse for sure, as far as the kind of Western environment. There's horses involved, he's a horse wrangler, and my wife read it and loves horses," Hemsworth added. "We have 10 or 11 horses back home and so she's like, 'You've got to do this.'"

When ET spoke with Costner at CinemaCon on Tuesday, the Yellowstone alum quipped that Hemsworth would have to "wait his turn," because "as long as I'm still young enough to play it, I'll play it."

But Costner had nothing but good things to say about the Marvel actor. "He's so handsome and he's so good," he added. "He's going to have to go find his [own] love story. [But] I'm glad he likes this one. If I reach a moment where I [don't] think I could do that, I would [reach out]. He's certainly one of our great leading men right now."

But until Hemsworth lands his great onscreen love story, fans can check out Transformers One, in which Hemsworth voices Orion Pax, a young Optimus Prime, alongside Henry, who voices D-16, a young Megatron.

"The big appeal to both of us, being fans of this universe, is the opportunity to tell a different story," Hemsworth said of the first animated film in the franchise in nearly four decades. The film serves as an origin story for Transformers' most beloved characters. 

Hemsworth continued: "We historically know them [as] mortal enemies, but here, they start off as friends. It's a great connection and bond, and they're two individuals who have something to prove. Then the evolution into the characters that we either love or hate is an interesting sort of journey, but there's a lot of heart in the film, a lot of comedic elements. So it was it was a big adventure."

"Yeah, me and Chris figured out the best way to bring the realness to it was to live together for the first three months of the film," Henry joked. "Just to do a lot of vocal exercises. You know, we even tried to do some of our own choreography which made it into the movie."

"It's really the juice," Hemsworth chimed in.

Brian Tyree Henry and Chris Hemsworth at Paramount Pictures' presentation during CinemaCon - Alberto E. Rodriguez/Getty Images for CinemaCon

The star-studded voice cast includes Scarlett Johansson as Elita-1 and Keegan-Michael Key as B-127, with Steve Buscemi, Laurence Fishburne and Jon Hamm rounding out the cast. Oscar winner Josh Cooley directs the film with a script written by Andrew Barrer and Gabriel Ferrari.

According to Paramount, the film is "the long-awaited origin story of how the most iconic characters in the Transformers universe, Orion Pax and D-16, went from brothers-in-arms to become sworn enemies, Optimus Prime and Megatron."

"It was nice to have the opportunity to come at it again and again and have it be orchestrated with Josh [at] the helm," Hemsworth shared. "It's different to a film experience where you kind of get one shot. You might get some reshoots, occasionally, but not to this extent."

"I really joined this knowing that Chris was going to be my Optimus Prime and you just kind of play in that way cause you can feel the essence of who they are and then you sometimes get a chance to see what they do and you go, 'Oh I need to do this completely different,'" Henry told ET. "It truly is [us] living out our imaginary selves when we were like 10, 11, watching these things Saturday morning. These characters are iconic to me and it's just a great adventure, especially to do it with this guy. It's wonderful."

Transformers One rolls out to theaters on Sept. 13.