Filmmaker Allen Hughes and his brother Albert direct Washington in the post-apocalyptic action film, but Allen reveals they had to fight to have the Training Day star cast as Eli.
He tells the New York Post, "I'm not gonna front - Denzel's black. His numbers are great, but internationally, does black travel? That's what really was going on. (The studio) was crunching the numbers."
The movie, which also stars Gary Oldman and Mila Kunis, opens in the U.S. on Friday (15Jan10).