Hernandez, the son of a famous sportscaster, grew up in Manila and started playing tennis at the age of 10.

[1] His first international title was a junior tournament in Osaka.

After briefly attending Hopkins High School in Minnesota as an exchange student, Hernandez played collegiate tennis for the University of Arizona.

[2] He won two medals with the Philippines at the 1962 Asian Games.

Hernandez won the 1963 Arizona Open on clay against a field of U.S. clay players.