By Will Robinson
March 21, 2016 at 12:00 PM EDT
Cate Cameron/The CW

Zack Snyder’s decision to not hire Grant Gustin as the Flash for the upcoming Justice League movies might have surprised some fans. But the Batman v Superman: Dawn of Justice director explains why the star of The CW series was never in the running to reprise his role on the big screen.

“I just don’t think it was a good fit,” he told the New York Daily News. “I’m very strict with this universe, and I just don’t see a version where … that (tone is) not our world.”

While the DC Comics films are known for their dark and serious tone, The CW’s superhero series The Flash and Arrow feature more levity.

“Even if Grant Gustin is my favorite guy in the world and he’s very good, we made a commitment to the multi-verse (idea),” Snyder continued, “so it’s just not a thing that’s possible.”

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Ezra Miller (The Perks of Being a WallflowerTrainwreck) was ultimately tapped to play Barry Allen and don the scarlet suit. His casting was announced about a week after Gustin’s show debuted.

Gustin admitted last month he would have loved to play the Flash in films, but penned a statement insisting he co-signed Miller’s casting. “I fully support Ezra Miller as Barry Allen and the Flash on the feature side of DC,” Gustin wrote in January. “I’ve never met the guy, but I think he is a fantastic and interesting actor.”

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Miller’s take on the Flash debuts with Friday’s Batman v Superman and will appear in a more significant capacity in next year’s Justice League — Part One and 2018’s The Flash. Expect a different take from Gustin’s.

“I’d like the character to have many dimensions. But really, I’d like him to have the usual dimensions we know and love, and then some extra ones that are part of the amazing consideration of this superhero,” Miller told EW in November. “I hope to realize him as a person, and I think what’s most exciting for me in superhero mythologies is when we feel the humanity of someone who is heroic — or the heroism of someone who is a flawed, deeply human person.”

Read Snyder’s full comments to the New York Daily News here.