His college baseball career with the Texas Tech Red Raiders included a 33 home run season in 1997, a record which still stands today.

Continued problems with his back, including increasing stiffness, prompted Dillon to retire during spring training 2003.

On May 18, 2005, he was recalled to the big leagues, making his MLB debut that same afternoon,[5] when (by an unfortunate coincidence) Marlins starting third-baseman Mike Lowell lost a foul pop-up by Milton Bradley of the Los Angeles Dodgers in the sun, causing Lowell to be struck by the ball in his face, subsequently forcing him to leave the game.

Dillon joined the Mazatlán Deer of the Pacific Mexican Winter League late in the 2004–2005 season, helping the team win the Caribbean Series championship.

Upon returning to American professional baseball, Dillon re-joined the Florida Marlins, who signed him to a minor league contract, on December 20, 2006.

On August 1, 2007, he was called up to the Brewers along with Elmer Dessens when pitcher Scott Linebrink left on bereavement leave and second baseman Rickie Weeks was sent down to Nashville.

Although expectations were high for Dillon in the off-season prior to the 2008 campaign,[6] he failed to make the big league roster out of spring training, instead finding himself back in Triple-A Nashville.

[8] On January 7, 2009, Dillon was designated for assignment to clear a roster spot for Jason Giambi and was sent outright to the minor leagues.

On December 20, 2013, Dillon was announced as the hitting coach for the Washington Nationals’ AAA affiliate Syracuse Chiefs.