A native of Bellerose, New York, Schaeffer attended high school at Holy Cross in Flushing. He stayed in his home state to attend college, electing to play for the Redmen of St. John's. In three varsity seasons spanning between 1970–71 and 1972–73, Schaeffer established himself as one of the premier players in program history. During his first season he averaged 14.4 points and 6.3 rebounds per game, followed by 17.1 points and 6.2 rebounds per game the following season as a junior. He was voted a third team All-American by the Associated Press and United Press International, among other accolades. Then, as a senior in 1972–73, Schaeffer averaged a still-standing school record 24.7 points per game behind a then-school record.594 shooting percentage. The Met Basketball Writers Association selected him as the Haggerty Award winner, which is given annually to the best male collegiate basketball player in the New York City metropolitan area. For his college career, Schaeffer accumulated 1,484 points and 622 rebounds.
Professional
The Los Angeles Lakers selected Schaeffer in the second round in the 1973 NBA Draft. Despite being drafted to the NBA, he chose instead to play in the American Basketball Association, which at the time was almost on par with the NBA in terms of popularity. In his rookie season in 1973–74, he played for the New York Nets who won the ABA championship. Schaeffer played a second full season with the Nets the following year as they failed to defend their title. In the off season he joined the Allentown Jets in the Eastern Professional Basketball League. They finished second in the regular season standings but went on to win the EPBL championship, two games to one, over the Hazelton Bullets. In 1975–76, what would be Schaeffer's last as a professional basketball player, he played in 20 regular season games for the Nets before being traded on January 7, 1976 to the Virginia Squires. While playing in 31 games for the Squires, he averaged a career high 6.6 points per game. The Nets, unfortunately for Schaeffer, would go on to win the 1976 ABA championship at the end of the season. In 137 ABA games played, he scored 802 points and grabbed 289 rebounds.
