Coach Mattison was a local standout at Lancaster Catholic High School before going on to play collegiate baseball. Mattison was named NJCAA Division II National Player of the Year after leading the country in batting average (.527), hits (108), and RBIs (87) with 24 doubles, four triples, and 12 home runs. Coach Mattison was then drafted in the 16th round by the San Diego Padres and played in their organization for 2 years.