[1] Eustis enrolled at Wesleyan University, where he played football as a fullback and end from 1911 to 1913.
[1][2][3] The New York Times described Eustis as "the mainstay on [Wesleyan's] football team for three years, playing full back and end with equal ability.
"[4] In February 1914, while he was still a student, Eustis was hired as the new head football coach at Wesleyan.
[5] He served as Wesleyan's head football coach from 1914 to 1915 and compiled a record of 10–7–1.
[7][8] His brother, Elmer T. Eustis, was the assistant football coach on the 1914 NYU Violets team.