In a major-league career that lasted through 1985, Thomas played for eight teams, mostly on the West Coast. In one of his best seasons, he hit.276 for the 1975San Francisco Giants, collecting 48 runs batted in and 28 stolen bases, both career highs. He was traded along with Bill Greif and Mark Schaeffer by the Astros to the San Diego Padres for Dave Roberts on December 3, 1971. Thomas said that he was often immature and unable to deal with the stressors of the game. Dusty Baker became fond of Thomas while they played for the Dodgers, but many people in baseball found Thomas to be an agitator. "Let's put it this way: Derrel Thomas does things that make it easy to hate him," Dodgers teammate Reggie Smith said. Padres manager Roger Craig said Thomas "plays hard and he's a showman-type player... If he has to play the villain role to get attention, he'll do it." After the 1985 season, Thomas' name was brought up in the Pittsburgh drug trials. Though he was not suspended, he was unable to find another major-league team to sign with. He signed with an independent team, the San Jose Bees, but he did not fit in well with his teammates and he was cut before the 1986 season started. Following his playing career, Thomas briefly coached at Los Angeles City College and was the first manager of the Boise Hawks in 1987, then an independent team in the Class A-Short SeasonNorthwest League. In June of that year, the Hawks faced the Bend Bucks, managed by Mel Roberts, marking the first time outside of Negro league baseball that two black managers faced each other in a professional regular-season game. Thomas was fired during his first season in Boise. By 1988, he was managing a bar and coaching baseball at Leuzinger High School. Before a 1989 game, several players were late for the team bus, and though the players drove to their game, he would not allow them to play. Several players quit the team in protest and Thomas resigned. In December 1991, Thomas was hired as a baseball coach at Dorsey High School. In March, a Dorsey baseball player fatally shot himself on the team bus while playing Russian roulette. Thomas was arrested the next month for attempting to purchase 22 pounds of cocaine. He was placed on probation; his probation was extended after a 1997 drug possession arrest. As of 2009, he was a member of the Los Angeles Dodgers organization serving as a representative of the Dodgers Legend Bureau.
