He played in Major League Baseball (MLB) for the San Francisco Giants, Montreal Expos, Texas Rangers, and Oakland Athletics from 1991 through 2001.

Following high school he attended Pima Community College to continue his baseball career.

He helped lead the team to the 1986 College World Series where they won the national title.

[2] Gil Heredia made his debut with the San Francisco Giants in 1991, and appeared in 20 games from 1991–1992.

After his playing career was over, Heredia became a minor league pitching coach in the Arizona Diamondbacks organization.