Sweeney shared two surprising photos of herself to Instagram and was nearly unrecognizable in the pics, most notably because of her hair. Gone was the dark blonde color and in its place, brunette curls and curly bangs. Her hair is pulled back in a low ponytail and she wears a red tank, gray sweatpants, and retro high-top sneakers.

Sydney Sweeney is undergoing quite the transformation for her next film role. The 27-year-old is set to star in a still-untitled biographical sports drama about boxer Christy Martin, and it's clear she's already physically embodying the role.

David Michôd will direct the film, which is currently untitled and follows the true story of Martin’s rise to being one of the most well-known female boxers in 1990s America. Ben Foster, Merritt Wever, Ethan Embry and Katy O’Brian also star in the biopic.

Sweeney looked completely unrecognizable as she swapped out her golden bombshell locks for the shaggy new style while getting into character for her new role as Christy Martin. Th

Who’s that girl? Sydney Sweeney usually plays a blonde bombshell, but the 27-year-old looked unrecognizable when she morphed into boxer Christy Martin while filming a biopic about the latter’s life. In photos obtained by The Post,