A 6-foot-7, 230-pound center, Schoon played for Valparaiso University during the 1940s, gaining fame for his ability to defend top-ranked player George Mikan of DePaul University. Schoon then played professionally in the BAA, NBL, NBA, and NPBL as a member of the Anderson Packers, Detroit Falcons, Flint Dow Chemicals, Sheboygan Redskins and Denver Frontier-Refiners.
Schoon is the last full-time player surviving from the Sheboygan Red Skins' 1949-50 NBA team. He platooned with Noble Jorgensen at center and played in all 62 games for the Red Skins that season, averaging eight points and shooting a team-best 41 percent from the field. Sheboygan's greatest conquests that season were victories over the New York Knicks, Rochester Royals, Syracuse Nationals and Minneapolis Lakers at the Sheboygan Auditorium and Armory. The Red Skins advanced to the NBA playoffs where they nearly eliminated the Western Division champion Indianapolis Olympians in a best-of-three series.
With the NPBL's Denver Frontier-Refiners in 1951, Schoon scored 363 points in 31 games, an 11.7 point average. He set a professional basketball scoring record with 64 points in a 99-72 victory over the Kansas City Hi-Spots on Jan. 21, 1951, at the Denver Auditorium. That record is currently held by Wilt Chamberlain, who scored 100 points in a 1962 NBA game.
The Frontier-Refiners compiled an 18-16 record, but the team moved to Evansville late in the season and Schoon's professional career ended.
Schoon was elected to the Valparaiso Athletic Hall of Fame in 2000.