Quarles played college football in Vanderbilt earning second-team All-Southeastern Conference honors as a senior and signed as an undrafted free agent by the Miami Dolphins in 1994 but was cut in training camp.

Quarles then played for two seasons (1995-96) with the Canadian Football League's BC Lions before signing with the Buccaneers as a free agent in 1997.

Quarles also holds the record for the longest play in Buccaneers' history with a 98-yard interception return for a touchdown against the Green Bay Packers in 2001.

[4] Quarles is married to his wife, Damaris, and have three children together: a daughter, Gabriela Nicole, and sons, Shelton Eugene Jr. and Carlos Antonio.

Upon retiring Quarles was appointed by Florida Governor Charlie Crist to the board of the Tampa Bay Area Regional Transportation Authority.