[1] As a child, Boone hung out in the Phillies clubhouse with Pete Rose Jr., his brother Aaron, Ryan Luzinski, and Mark McGraw.

Boone attended the University of Southern California and played for the team, but left after his junior year of college when he was drafted by the Seattle Mariners in the fifth round.

As a member of an All-Star family, he is the son of Bob Boone, a catcher for the Philadelphia Phillies, California Angels, and Kansas City Royals (1972–1990) and later a manager with the Royals and Cincinnati Reds; his brother Aaron was a third baseman who has played with the Reds, New York Yankees, Cleveland Indians, Florida Marlins, and Houston Astros, and is now the manager of the Yankees.

Boone started his playing career with the Seattle Mariners, where he set the club record for home runs in a season by second baseman in 1993 (12 in 76 games)[6] but was traded that same year to the Cincinnati Reds along with Erik Hanson.

In his final year with the team, Boone earned his first All-Star Game appearance as a replacement for the injured Sammy Sosa.

During their postseason run, Boone posted a .370/369/.481 slash line that included a 7 for 14 World Series performance where the Braves ultimately lost in a sweep by the New York Yankees.

Boone started in the All-Star Game at Safeco Field, received a Silver Slugger Award, and finished third in the AL MVP voting.

[18] On March 21, 2008, Boone was reassigned to minor league camp after hitting .189 and began the season with the Columbus Clippers, the Nationals Triple-A affiliate.

On May 27, 2010, after managing just four games, the Seals announced Boone was leaving the team permanently to deal with "family matters".