Bradley Cooper Says He 'Cried Pretty Hard' Watching 'Guardians of Galaxy Vol. 3' (Exclusive)

Cooper stars as Rocket Raccoon in the 'Guardians' saga.

Bradley Cooper is bidding farewell to Rocket Raccoon -- at least for now!

ET's Ash Crossan spoke to Cooper at the premiere of the final installment in the Guardians saga, Guardians of the Galaxy Vol. 3, where he revealed that he got pretty emotional watching a cut of the film, especially when he saw how Rocket's story unfolds.

"He did talk to me about that initially too, that he had this sort of end game for Rocket, and us learning about his origin," Cooper said of director James Gunn's plans for the franchise's final film. "You never know if that's actually gonna happen, and then low and behold, we get to this third script and I read it, and I go, 'Oh my gosh that's exactly what he talked about.'"

He continued, "It was -- emotional's the right word. I watched a cut of it a while ago, and I cried pretty hard. I mean, it's pretty hardcore. Little Rocket -- he went through a lot, dude. He went through a lot."

While what Cooper was able to tease is just "the least of it," the A Star Is Born actor said he'd gladly continue Rocket's journey should Gunn give him the call.

"I go wherever James tells me," he said, and that may include a jump from the MCU to the world of DC Comics, where Gunn has a few projects in production.

"No, but I just think he's incredible," Cooper said of his plans to join DC. "I love Peacemaker. I love that series he did. I thought that was incredible, like blew me away."

He added of Gunn, "And I just think he's -- as I said, I'm just glad he's working, making movies and television."

previously released trailer for the film alluded to Rocket being at its center with flashes of his origins as an innocent animal who gets turned into what he is today through cruel experiments. 

But, as Marvel President Kevin Feige said in ET's exclusive look behind the scenes at the final film, the trilogy's heart lies in its found family, which is tested like never before in this new installment. "Everything that drives it is that emotional center of all these characters who are all outsiders," Gunn added.

"It's another rock opera. It's really fantastic and it wraps it up in a way that really only James could," the film's star, Chris Pratt, noted.

Guardians of the Galaxy Vol. 3 rockets into theaters May 5.