[1] While in high school, Carroll was the Washington Post All-Met Player of the Year, was twice named to the Parade All-American team, and led the West Springfield Spartans to the final of the Virginia state tournament in 1998.

Named captain as a sophomore, Carroll tied the school record for most assists in a game with three and finished the year as a second-team All-ACC selection.

[2] Unfortunately for him, coach Ray Hudson preferred a lineup dominated by veterans, and although he saw time in U.S. Open Cup competition, Carroll did not appear in any regular season games.

Carroll lost his starting role with United to fellow defensive midfielder Clyde Simms midway through the 2007 season, but still had a productive year, with 4 assists to his credit.

It was announced on 27 November 2006 that Carroll was on trial with French club Olympique de Marseille with hopes for an eventual transfer.

In his first game for the full national team (a World Cup qualifier vs. Panama on October 12, 2005), he was named Man of the Match.