He played seven seasons in the National Basketball Association (NBA) before transitioning to an extensive professional career overseas in Europe.

[1][2] Douglas played at Alabama for coach CM Newton, who would start five black players in a time of racial turbulence and progress.

[7] The team would lose in the next round, 74–69, to eventual national champion Indiana, and finished the season ranked 6th in polls.

[1] Douglas was also a member of the United States national basketball team that won a gold medal at the 1975 Pan American Games.

[10] Douglas was the first Crimson Tide player to be selected in the first round of the NBA draft when he was chosen fourth overall by the Detroit Pistons in 1976.

Douglas then pursued overseas opportunities, initially with Limoges CSP in France, helping the team to win the 1983-84 LNB Pro A league title, and then in Serie A in Italy, with Fortitudo Bologna (1984–87) and then with Olimpia Basket Pistoia (1987–91) where, for two seasons (1987–1989) he paired with Joe "Jellybean" Bryant, who was raising his son Kobe Bryant.

Douglas won the 2014 NCAA Division II Coach of the Year award, despite having been suspended for six games in the season after two players suffered heat exhaustion in pre-season workouts, and would then leave the university after a contract dispute.

[18][30] Douglas was appointed as head coach of the boys' basketball team at Barbour County High School for the 2023–24 season.

[31] Douglas appeared as a member of the Detroit team in the cult classic basketball film The Fish That Saved Pittsburgh in 1979 alongside Pistons teammates Lanier, Eric Money, John Shumate, Chris Ford, and Kevin Porter.