hernandez broke into the business of race calling in 1927 for agua caliente racetrack at tijuana, being developed by the first-ever race caller, steward george schilling, who on 5 february 1927 called the first race at the mexican track. in 1932, he became the first race caller at tanforan. in the coming years, he became the premiere race caller on the west coast, at a time when most mexicans and mexican americans were being repatriated to mexico due to america's great depression. in the late 1930s, alfred vanderbilt, jr. hired hernandez to call the races at pimlico race course and belmont park. while there, hernandez encountered some discrimination when he was seen in public with his wife pearl, an anglo-american. in 1950, hernandez called the kentucky derby for fans at churchill downs. a recording of his call was later distributed to over 60,000 racing fans.