Mark Kotsay's journey through Major League Baseball began when he was selected by the Florida Marlins as the ninth overall pick in the 1996 MLB Draft. A standout at Cal State Fullerton, where he won the Golden Spikes Award, Kotsay quickly transitioned to the professional level, making his MLB debut with the Marlins in 1997. Known for his strong arm and defensive skills, he initially played as a center fielder, a position that highlighted his athleticism and fielding capabilities.

During his time with the Marlins, Kotsay contributed to the team's success, including their 1997 World Series victory, although he did not play in the postseason. His tenure with the Marlins lasted until 2000, when he was traded to the San Diego Padres. In San Diego, Kotsay continued to develop as a reliable outfielder and hitter. His time with the Padres saw him achieve a career-high batting average of .298 in 2002, demonstrating his ability to contribute offensively as well as defensively.

In 2003, Kotsay was traded to the Oakland Athletics, where he spent four seasons. His performance with the Athletics was marked by consistency and reliability. In 2004, he batted .314, one of the best seasons of his career, and played a crucial role in the Athletics' lineup. Kotsay's defensive prowess was also on display, as he was known for making difficult catches look routine and for his accurate throws from the outfield.

Kotsay's career continued with stints at several other teams, including the Atlanta Braves, Boston Red Sox, Chicago White Sox, and Milwaukee Brewers. Each stop in his career showcased his adaptability and ability to contribute to different teams in various roles. While his offensive numbers fluctuated, his defensive skills remained a constant asset.

Injuries began to take a toll on Kotsay's playing time and performance in the latter part of his career. Despite these challenges, he remained a respected figure in the clubhouse, known for his leadership and experience. His final seasons were spent with the San Diego Padres, where he returned in 2012 and played until his retirement in 2013.

Throughout his career, Kotsay was recognized for his strong work ethic and professionalism. He finished with a career batting average of .276, 127 home runs, and 720 RBIs. Beyond the statistics, Kotsay's career was characterized by his defensive skills and his ability to play multiple outfield positions effectively.