Schilling was a left-handed first baseman who hit leadoff on the 1974 Meramec Community College team that won the JUCO national championship in Grand Junction, Colorado. His batting average in the JUCO World Series was .381 and his on-base percentage was .600. In the title game, he was on base five times with three hits and he scored two runs. The prior season at Meramec, he helped the team win the Missouri junior college championship with a team-high .361 average. He led the team in hits, runs scored, triples and stolen bases.

In 1975-76, Schilling played on scholarship for the University of Nevada at Las Vegas. In 1975, he made the All-Conference team with a .425 batting average. The next year he was named to the all-tournament team at the Colorado Invitational Tournament.

Schilling began his baseball career in 1962 with the St. Lou Athletic Club in the Khoury League. From 1963-69 he played first base for the Southwest Kiwanis in the Khoury League, and played first base at Southwest High School from 1970-72. Southwest won the Public High School League championship in 1971 and 72. Schilling batted .365 in 1972 and was named to the All-PHL team. In three years at Southwest High, he hit .363.

From 1970-72, Schilling played first base for the Gardenville-Affton American Legion Post 300. In 1970, he battled .400 in 17 games. In 1971, he hit .500 in 17 games with 23 hits, 25 walks and 12 stolen bases.

Schilling played in the Heine Meine semi-pro league for Johnny Mac Juniors in 1971, the Johnny Mac Intermediates in 1972 and E.G. Hydraulics in 1973. From 1974-76, he played first base and left field for the Fenton Vets. In 1976. John was selected to the St. Louis County League all-star team. In 1974-75, Schilling worked as an instructor at a baseball camp in the St. Louis area.