D.C. United Carroll was selected 11th overall in the
2003 MLS SuperDraft by
D.C. United. 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.
Peter Nowak replaced Hudson following the 2003 season, and soon expressed incredulity that a player as talented as Carroll saw no playing time under Hudson. Carroll was a fixture in Nowak's lineup for the first game of the 2004 season, and would remain there all year long, appearing in all 30 of the team's games, starting 26 of them, earning his first MLS assist, and winning the
MLS Cup. In 2005, he led the team in minutes and games played, scored his first league goal, added three more assists, and led MLS in consecutive games played, at 62. Carroll was one of three players nominated for the 2005
MLS Fair Play Award. Carroll started 31 games for the club in 2006, with 1 goal and 3 assists. 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. However, on 23 January 2007 it was announced that Carroll had re-signed with D.C. United.
Columbus Crew On November 21, 2007, Carroll was selected as part of the
expansion draft to join the new
San Jose Earthquakes club. On November 26, he was traded to the
Columbus Crew in exchange for
Kei Kamara. In June 2010, Caroll signed a four-year contract extension with the Crew. Between 2004 and 2016 he made at least 21 appearances for 13 different seasons. Upon retirement he was praised for his professionalism and leadership. ==International career==