He joined Atletico Madrid soccer club as a youth player, but his life took a turn when tragedy struck.
His senior year, San Jose State soccer coach Jules Menendez approached Hernandez about playing for him.
In 1976, Hernandez coached Leland High School (San Jose, California) varsity men's soccer team to its first Central Coast Section championship and in 1982, Hernandez was also the assistant coach at San Jose State men's soccer.
Hernandez coached the Gunderson High School (San Jose, California) varsity men's soccer team to its first Central Coast Section playoff berth, beating previous Central Coastal Sectional champion Watsonville HS 11–1 in a 1st-round match.
In 1983, Presentation High School in San Jose hired Hernandez, becoming the head coach of the girl's varsity soccer team.