Prior to joining Whitecaps FC, Hertzog was drafted 13th overall by New York Red Bulls in the 2011 MLS SuperDraft after signing a Generation adidas contract. During his first two professional seasons, the striker made five first team appearances.
From 2008 to 2010, Hertzog played National Collegiate Athletic Association (NCAA) soccer for Penn State University. As a member of the Nittany Lions, the Reading, Pennsylvania, native scored 33 goals and recorded 14 assists in 61 matches. In 2010, his junior year, Hertzog led NCAA Division I in goals scored when he connected 20 times and was named a semifinalist for the MAC Hermann Trophy – annual NCAA award present to the nation’s best college soccer player. In between his collegiate seasons, Hertzog played for Reading United A.C of the USL Premier Development League (PDL), scoring four goals and recording one assist in 12 matches.