The Mad Men actress will star alongside Naomi Watts and Liev Schreiber, Variety reports.
Jeff Feuerzeig and Jerry Stahl's script depicts the life story of the New Jersey heavyweight boxer Chuck Wepner, who fought 15 rounds with boxing legend Muhammad Ali in 1975.
Wepner, to be played by X-Men star Schreiber, was the inspiration for Sylvester Stallone's character Rocky Balboa.
Variety speculates that Hendricks and Watts could play Wepner's former wives.
Hendricks is also attached to the Neil LaBute-penned drama Seconds of Pleasure, a series of vignettes set in an airplane.