John began his baseball career at age seven playing Wilmette Little League. He went on to play varsity baseball at New Trier High School while studying under the instruction of Eric Soderholm of The Chicago White Sox. In 1992, after 3 years of college baseball at St. Andrews College in North Carolina, John was drafted by The St. Louis Cardinals. He went on to play professionally until the fall of 1995.

John then began instructing North Shore kids while he earned his degree in finance from The University of Illinois at Chicago. He and Peter Dallas opened The North Shore Baseball Academy in March of 2000.