 His younger brother, Marcus, was a running back at Georgia Tech from 2015 through 2016 before he transferred to James Madison in 2017.James Madison is the alma mater of Marshall's father, Warren Keith Marshall Sr, who is JMU's career leader in rushing yards (4,168, 1982–86).Warren is a Madison Hall of Famer, and played for the Denver Broncos after they selected him in the sixth round of the 1987 NFL Draft.