After spending the 1986–1987 season with the Jacksonville (later Mississippi) Jets, Upshaw signed with the West Palm Beach Stingrays of the USBL in the spring of 1987.[5] The Jets cut Upshaw on May 26, 1987, due to injury[6] but recalled Upshaw in late June.[7] Upshaw returned to the Mississippi Jets later in 1987 and was selected to the 1988 CBA All-Star Game.[8] Upshaw later played for the CBA's Rapid City Thrillers for the rest of the season.[9]
Upshaw signed with the Palm Beach Stingrays in June 1988.[9] Upshaw then played for the CBA's Albany Patroons for most of the 1988–1989 season. In January 1989, Upshaw signed with the NBA's Miami Heat. In two ten-day contracts with the Heat, Upshaw played in nine games and averaged 6.8 points, 1.5 rebounds, 3.7 assists.[10] Upshaw re-joined the Patroons on February 7.[11] The NBA's Boston Celtics signed Upshaw in March 1989 to relieve the injured Ramón Rivas.[12] Upshaw played in 23 games for the Celtics averaging 6.3 points, 1.4 rebounds, and 2.2 assists.[10]The Boston Globe noted at the time, "Upshaw has brought to Boston instant up-tempo offense along with tough, chest-to-chest defense against some of the league's best (Isiah Thomas, Mo Cheeks), as well as a certain sang froid in delivering the big jumper."[13]
A week after being waived, Upshaw re-signed with the Celtics on November 24, 1989, and was waived again on December 26, 1989. In 14 games at the beginning of the 1989–90 season with Boston, Upshaw averaged 7.0 points, 1.6 rebounds, and 4.2 assists.[10]
Upshaw signed the first of two ten-day contracts with the Dallas Mavericks on January 6, 1990, and played three games with the Mavericks with very few minutes per game.[10] On February 28, 1990, Upshaw signed a season-long contract with the Golden State Warriors and averaged 5.6 points in 23 games.[10]
Upshaw signed with the Dallas Mavericks on November 12, 1990, and re-signed on December 29 five days after being waived. In 48 games, Upshaw had one start and averaged 5.6 points.[10]
Upshaw was meted a lifetime ban from the PBA for violating the league's anti-drug policy. But he gained notoriety with Filipino basketball fans for showing his butt to the crowd during a televised game in 1992.[16]
^MacMullan, Jackie (April 2, 1989). "How did everyone else miss out on Kelvin Upshaw?". Deseret News. Archived from the original on January 16, 2014. Retrieved January 13, 2014. Originally published by The Boston Globe as "Credit Celtics with a steal; Signing Upshaw a timely maneuver."
^"Sports shorts". Associated Press News. January 4, 1992. Retrieved January 13, 2014.