The film, to be directed by Dito Montiel, will begin filming next month in Louisiana, reported Deadline.
Courtney, 28, joins Shia LaBeouf, Gary Oldman, Kate Mara and Toby Kebbell in the story of Gabriel Drummer, a haunted Afghanistan war veteran who attempts to come to terms with his past while searching for his family in a post-apocalyptic America.
Courtney will play the role of Devin, Gabriel's best friend who served with him in the war. Dawn Krantz, Stephen McEveety, and Jon Burton are producing the film.