James Gunn is defending " Guardians of the Galaxy Vol. 3" star Chukwudi Iwuji from "racist" trolls.

Earlier this week, the director shared an Instagram post touting Iwuji's role as the High Evolutionary in the upcoming Marvel film, saying, "Can't wait for you all to meet this guy."

MORE: New trailer for 'Guardians of the Galaxy Vol. 3' out now: Watch here

One social media user took issue with the casting choice in the comments, lamenting "another white guy they made into a black guy" and asking why they couldn't "just leave him white" or "pick a different minority." They called the decision "woke."

"Sad and pathetic. They're picking based on race and [what's] PC and not on acting and [what's] established," the user wrote.

PHOTO: Chukwudi Iwuji is shown as The High Evolutionary in Marvel Studios' Guardians of the Galaxy Vol. 3.
Courtesy of Marvel Studios
Chukwudi Iwuji is shown as The High Evolutionary in Marvel Studios' Guardians of the Galaxy Vol. 3.
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Gunn fired back in a reply, writing, "I chose the best actor, period, and the best person for the role. I don't give a s--- what ethnicity @chukwudi_iwuji is, so stop with your racist presumptions on WHY he was chosen."

The director didn't stop there, adding, "And, by the way, he’s playing a guy who's almost always purple in the [comics]."

Iwuji most recently appeared as black-ops leader Clemson Murn in the DC Extended Universe series "Peacemaker" on HBO Max, also directed and created by Gunn.

In addition to Iwuji, "Guardians of the Galaxy Vol. 3" stars Chris Pratt as Peter Quill or Star-Lord, Karen Gillan as Nebula, Pom Klementieff as Mantis, Zoë Saldana as Gamora, Sean Gunn as Kraglin, Vin Diesel as Groot, Dave Bautista as Drax the Destroyer, Will Poulter as Adam Warlock and Maria Bakalova as Cosmo the Spacedog.

According to the movie's official synopsis, in the latest "Guardians" installment, the "beloved band of misfits are looking a bit different these days."

"Peter Quill, still reeling from the loss of Gamora, must rally his team around him to defend the universe along with protecting one of their own. A mission that, if not completed successfully, could quite possibly lead to the end of the Guardians as we know them," the synopsis reads.

"Guardians of the Galaxy Vol. 3" hits theaters May 5.

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