The "Barbie" movie might have broken box office numbers for Warner Bros., but not everyone was on board for the blockbuster before production began.

Professional wrestler turned actor John Cena, who made a brief cameo in the film as Merman Ken, says an agency he was working with discouraged him from taking the role because they thought it was "beneath" him.

Cena prefaced the revelation by explaining that he doesn't work with a publicist, so his team really only consists of his manager. He does, however, work with an agency to secure roles. He's currently signed to WME Agency, although he never referenced them directly.

MARGOT ROBBIE AND RYAN GOSLING WERE 'MORTIFIED' WHEN PICTURES FROM 'BARBIE' SET WENT VIRAL

John Cena in a blue suit with a bright gold tie and pocket square smiles on set of the TODAY show

John Cena was encouraged by an agency he was working with to not take on the role of Merman in the "Barbie" movie. (Nathan Congleton/NBC via Getty Images)

"They're just going on what they know, and what they know is, this entity, this commodity, gravitates towards these things. We should stay in this lane. But I'm not a commodity. I'm a human being. And I operate under the construct of every opportunity is an opportunity," he shared on "The Howard Stern Show."

"I read the script of the movie, I tried my hardest to be in the movie, but we were filming ‘Fast [& Furious],’ filming next door," he explained. After getting connected with producer and star Margot Robbie, he says a plan came to light.

Margot Robbie wearing choker pearls and a light pink dress with a furry top

Margot Robbie recruited John Cena to be in "Barbie." (Wiktor Szymanowicz/Anadolu Agency via Getty Images)

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"Margot was like, ‘We'll make you a Merman, you'll be in it for a half a day.'"

Although Cena was into the concept, the agency was not. "But I think the perspective from an agency's standpoint was, ‘This is beneath you,'" he admitted. "Which I get, I get that. But also to the agency's credit, immediately they acquiesced when I was like ‘No, we’re gonna do it.'"

John Cena in a navy striped blazer fends questions from the media

John Cena says he went against an agency's suggestion and took the "Barbie" role. (Jason Koerner/Getty Images)

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"But all they can do is offer their guidance," he added. "They're not ultimately making the choice. And their guidance is, ‘Hey, truly, trickle-down economics from this may take you out of these lead lap slots.’ And I get all of that. I've always operated under the philosophy good work gets you another chance."

While doing promotion for the film in July with co-star Ryan Gosling, Robbie was asked about Cena joining the flick and confirmed she had something to do with it.

Margot Robbie in a plaid dress as Barbie in "Barbie" standing in front of a pink mirror without any glass

Margot Robbie not only starred but also produced "Barbie." (Courtesy Warner Bros. Pictures)

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"While we were shooting in London, I ran into him at a restaurant, and we'd worked together before," she told Chris Van Vilet.

"I was like, ‘Do you wanna come be a Merman in ‘Barbie'?' And he was like, ‘Uh, yeah.' And I was like, ‘Surely he’s not gonna agree to it just like that.' And he did. . . . But he's so awesome like that."

Cena's manager as well as his representative at WME did not immediately respond to Fox News Digital's request for comment.