Here's why Zack Snyder wouldn't cast Grant Gustin for the DC movies

Grant Gustin's performance as Barry Allen in CW's The Flash has drawn rave reviews from die-hard DC Comics fans and newbie fans alike -- which is why they were all the more shocked when Ezra Miller was cast as the Flash on the big screen.

But despite Gustin's popularity, Batman v. Superman director and the helmer of the DC movie universe, Zack Snyder said he never even considered Gustin for the part.

In an interview with The New York Daily News, Snyder explained why Gustin's light-hearted take on the DC superhero wasn't right for the gritty DC movie universe he was building.

I just don’t think it was a good fit … I’m very strict with this universe and I just don’t see a version where … that (tone is) not our world. 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.

A darker tone for the movie version is a bit contradictory to what Snyder told The Hollywood Reporter earlier this month about his plans, which he described as "a little lighter" than Wonder Woman, and focused on a "millennial" take on the Scarlet Speedster. Which, funnily enough, pretty much describes the CW Flash.

Gustin earlier this year told fans he "fully supports" Miller's casting as the movie version of the Flash, and that there were no hard feelings. And while we won't get to see him meeting up with Henry Cavill's Superman or the Batffleck, at least we'll get to see him and Supergirl cross paths this month.

Batman v. Superman hits theaters March 25.