Mack played for Richard Gahr High School in Cerritos, California, from 1978-1981.

Upon graduation, he accepted an athletic scholarship to play for the UCLA Bruins baseball team where he starred from 1982-1984.

His career statistics include a .299 lifetime batting average, 80 home runs, and 398 RBIs in 923 games.

Notably, he was a key component of the Twins' 1991 World Series championship team.

On March 6, 2006, having been informed of the grave condition of former teammate Kirby Puckett, who had gone blind in one eye a few years before, due to glaucoma, and who had suffered a massive stroke the previous day, Mack flew to Arizona to be with him along with a number of other current and former Twins.