Matthew McConaughey was almost the king of the world.

An upcoming book by late “Titanic” producer Jon Landau has reportedly revealed why the “True Detective” star, 55, lost the lead role in James Cameron’s 1997 blockbuster to Leonardo DiCaprio.

In his newsletter “What I’m Hearing,” Puck’s Matthew Belloni published an excerpt from Landau’s book “The Bigger Picture,” which reveals details about McConaughey’s screen test for the role of Jack in “Titanic.”

“We brought him in to do a scene with Kate (Winslet),” the book says, according to Puck. “You want to check for chemistry, not just how people look on film but how they interact.”

Matthew McConaughey attends the "Rivals of Amziah King" premiere during the SXSW Conference and Festival in Austin, Texas, on March 10, 2025.

Matthew McConaughey attends the “Rivals of Amziah King” premiere during the SXSW Conference and Festival in Austin, Texas, on March 10, 2025.

“Kate was taken with Matthew, his presence and charm. Matthew did the scene with the drawl. ‘That’s great,’ said Jim (Cameron). ‘Now let’s try it a different way.’ Matthew said, ‘No. That was pretty good. Thanks.’ Let’s just say, that was it for McConaughey.”

USA TODAY has reached out to Disney, owner of the book’s imprint, Hyperion Avenue.

McConaughey has previously discussed being up for the role of Jack in “Titanic” in numerous interviews. During a 2019 appearance on “Watch What Happens Live,” he claimed his audition “went really well,” so much so that he thought he landed the part.

“(It went) well enough where when I left, I was being glad-handed and slapped on the back like, ‘This is what we’re looking for. You got it,'” he said. “Well enough where you get outside, you call your agent, and you go, ‘Oh, I nailed it. This is happening.'”

Matthew McConaughey attends the 2024 Kering Foundation's Caring for Women dinner on Sept. 9, 2024.

Matthew McConaughey attends the 2024 Kering Foundation’s Caring for Women dinner on Sept. 9, 2024.

McConaughey has also denied a rumor that he did get the role, but turned it down. Speaking on Rob Lowe’s “Literally!” podcast, he clarified, “I did not get offered that role. For a while there, I was thinking, ‘I’ve got to find that agent. They’re in trouble!’ Well, I didn’t ever get the offer.”

Though DiCaprio wound up playing Jack, he almost lost out on the part, too.

In a 2022 video interview with GQ, Cameron revealed DiCaprio nearly wasn’t cast because he didn’t want to do a screen test with Winslet.

“He said, ‘Oh, I don’t read,'” Cameron recalled. “I shook his hand and I said, ‘Well, thanks for coming by.’ He said, ‘Wait, wait, wait, you mean if I don’t read, I don’t get the part, just like that?’ And I said, ‘Oh, yeah, come on. … You’re going to read or you’re not going to get the part.”

According to Cameron, DiCaprio reluctantly agreed to do the reading with Winslet but had a “negative” attitude about it – “right up until I said action, and then he turned into Jack.”

This article originally appeared on USA TODAY: Matthew McConaughey as Jack in ‘Titanic’? Why he lost the role