Heyman's success in college led to his being selected first in the 1963 NBA Draft by the New York Knicks. During his first season with the team, he averaged 15.4 points per game and made the league All-Rookie Team. His playing time with the Knicks decreased during his second year, however, causing his scoring average to drop to just 5.7 points per game. Heyman parted ways with New York in 1965, and after brief stints with the Cincinnati Royals and Philadelphia 76ers, he left the NBA for the American Basketball Association in 1967.
He played in the ABA for the next three seasons, winning a league championship with the Pittsburgh Pipers in 1968 as he averaged over 20 points a game.