Rachel McAdams and Lupita Nyong'o join boxing drama

Long in development, the boxing drama is starting to take shape, beginning with the assembly of an all-star cast.

Although rumors suggested that Eminem would headline the film, the lead has ultimately gone to Jake Gyllenhaal. The actor will play a fighter trying to return to the ring after a personal tragedy.

On Thursday, Deadline.com reported that three other A-listers are on their way to joining the feature. Oscar winner Forest Whitaker ("The Butler") is in talks to play the boxer's trainer, while Rachel McAdams ("About Time", "Midnight in Paris") has been tapped to play the female lead.

The website also indicates that Lupita Nyong'o, who won the Oscar for best supporting actress for her role in "Twelve Years a Slave", is being courted to play a social worker who looks out for the fighter's young daughter.