The role is said to be of a "high-ranking Amazonian warrior." Pure speculation, but that could mean Hyppolyta, the Queen of the Amazons and mother of Wonder Woman/Diana Prince.
The 48-year-old actress would be making her return to comic book movies if she gets the part, as she previously played Dr. Chase Meridian in 1995's Batman Forever. Though, she might be better known for her roles in Days of Thunder, The Hours, Moulin Rouge! and Eyes Wide Shut.
Wonder Woman is being directed by Patty Jenkins (Monster) based on a screenplay by Jason Fuchs (Pan). Gal Gadot will star as Wonder Woman and Chris Pine (Star Trek Into Darkness) will costar as Steve Trevor. Wonder Woman is expected to begin filming later this month and will land in theaters on June 23, 2017.