ScarJo is expected to play an actress who gets pregnant as her film is about to start production, while Hill's role is still kept under wraps.
Two more big stars are added to the mix in "Hail Caesar" casting report. "Lucy" heroine Scarlett Johansson and "22 Jump Street" undercover police officer Jonah Hill are in negotiations to star in the Coen brothers' movie.
According Variety, ScarJo who happens to be expecting a baby with fiance Romain Dauriac is expected to play an actress who suddenly becomes pregnant as her film is about to go into production. Meanwhile, Hill's role is still unclear.
Josh Brolin and George Clooney are set to star in the film. Hill's "Jump Street" co-star Channing Tatum is in talks to play a movie star, Tilda Swinton will play a gossip columnist, and Ralph Fiennes will portray a director.
The movie follows Eddie Mannix, a Hollywood fixer tasked with keeping the scandals of the town's biggest stars from leaking out.