Reggie Harris, a right-handed pitcher, embarked on his Major League Baseball journey when he was drafted by the Oakland Athletics in the first round of the 1987 MLB Draft. His professional debut came with the Athletics, where he began to hone his skills on the mound. Harris's time with Oakland was marked by his development as a pitcher, although he faced challenges in securing a permanent spot in the rotation.

In 1990, Harris made his MLB debut with the Athletics, appearing in a handful of games. His tenure with Oakland was relatively short-lived, as he was traded to the Boston Red Sox in 1991. With the Red Sox, Harris found more opportunities to showcase his abilities, primarily as a relief pitcher. During his time in Boston, he worked to establish himself as a reliable option out of the bullpen, although consistency sometimes eluded him.

Harris's career continued with a move to the Philadelphia Phillies in 1993. His stint with the Phillies was brief, and he soon found himself transitioning to the Houston Astros. With Houston, Harris continued to pitch in relief, striving to maintain his place in the major leagues amidst the competitive environment.

The mid-1990s saw Harris moving between teams, including a return to the Athletics and a period with the Milwaukee Brewers. Throughout these transitions, he remained a journeyman pitcher, adapting to various roles as needed by his teams. His adaptability allowed him to extend his career in the majors, even as he faced the challenges of maintaining performance levels.

In 1997, Harris joined the Kansas City Royals, where he continued to contribute as a relief pitcher. His experience and knowledge of the game were assets to the teams he played for, even as he navigated the ups and downs of a professional baseball career.

Reggie Harris's time in Major League Baseball concluded in the late 1990s.