Sledge attended John F. Kennedy High School in Granada Hills, California and played college baseball at Long Beach State.

On September 29, 2004 he was the final out at the last Expos home game when he popped out to third base in 9-1 loss to the Florida Marlins On October 3, 2004, he recorded the final hit and RBI in Expos history when he drove in Jamey Carroll on an RBI single in a game against the New York Mets.

He was traded to the Texas Rangers along with fellow outfielder Brad Wilkerson and Armando Galarraga for second baseman Alfonso Soriano on December 7, 2005.

On November 29, 2007, Sledge was granted permission by the Padres to sign with the Hokkaido Nippon-Ham Fighters of the Nippon Professional League.

In October 2003, while training with the USA Olympic baseball team, Sledge became one of the first MLB players to test positive for performance-enhancing drugs.