Unlike the Marvel Cinematic Universe, DC is doubling down on multi-verse realities, where the TV shows and movies exist in completely separate worlds. However, that didn't stop fans from complaining when The Flash's Grant Gustin wasn't cast as the show's titular hero in the upcoming Justice League film franchise.

Instead, Ezra Miller will be playing the speedster in the movies, starting with a cameo in Batman v Superman: Dawn of Justice. And according to director Zack Snyder, Gustin was never even seriously considered for the role.

"I just don't think it was a good fit," Snyder told the New York Daily News. "I'm very strict with this universe and I just don't see a version where [Gustin's The Flash would work]... that [tone is] not our world."

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Unlike the Flash series, which leans heavily on comedy and heartwarming family relationships, the Justice League films are all about darkness and grit. But even if the Justice League films and The Flash had similar tones, Snyder said he still wouldn't have cast Gustin.

"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], so it's just not a thing that's possible," Snyder said.

Are you sad Gustin isn't the silver screen scarlet speedster?