There apparently were no other actors in Hollywood.

Leonardo DiCaprio may be the king of the world, but he lost his shot at becoming a rebel without a cause.

While speaking with Deadline about his Heat sequel/prequel novel, director Michael Mann revealed that he ended up making Heat — and abandoning a planned James Dean biopic — because he grew tired of waiting for his top choice for the role, DiCaprio, to age into the part.

"That was so weird about James Dean," Mann said. "It was a brilliant screenplay. And then it's who the hell could play James Dean? And I found a chap who could play James Dean, but he was too young. It was Leo. We did a screen test that's quite amazing. I think he must've been 19 at the time."

Movie star James Dean attends the Premiere of Sabrina on September 22 1954 in Los Angeles, California. (Photo by Michael Ochs Archive/Getty Images; 51st Annual Golden Globe Awards Leonardo DiCaprio (Photo by Terry McGinnis/WireImage)
Credit: Michael Ochs Archive/Getty; Terry McGinnis/WireImage

"And from one angle, he totally had it with him," he continued. "I mean, it's brilliance. He would turn his face in one direction and we see a vision of James Dean, and then he'd turn his face another direction and it's no, that's a young kid. He respectfully undid the James Dean bio for me."

DiCaprio was regarded for his baby-face good looks early in his career, a boyish charm that lent itself naturally to titles such as Romeo + Juliet and Titanic. But it is a bit perplexing that he wasn't old enough to portray Dean, who was, in fact, only 24 when he died after making three films. Mann could've returned to the biopic after Heat when DiCaprio had aged a bit more, or selected another actor from the crop of young talents on the rise in the mid-1990s.

Dean's short life has since been chronicled on screen, most notably by James Franco in a 2001 TV movie and by Dane DeHaan in 2015's Life (coincidentally, both stars have also played Harry Osborn in Spider-Man films).

But for Mann, it was either DiCaprio or Dicapri-no for his Dean project.

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