Cordero played in Major League Baseball (MLB) for the Montreal Expos / Washington Nationals and Seattle Mariners.

In February 2006, Cordero and his teammate Brian Schneider were chosen to play for Team USA in the World Baseball Classic.

Cordero admitted he was distracted by the illness of his ailing grandmother,[3] and missed six games for personal bereavement leave.

On June 13, Cordero (at age 25 years and 86 days) became the second youngest player in baseball history to reach 100 saves in a career.

[citation needed] Cordero missed almost all of the 2008 season after undergoing surgery to repair a labrum tear, an injury he suffered in April.

[6] On March 12, 2009, Cordero signed a minor league contract with the Seattle Mariners with an invitation to spring training.

He was to compete for the closer role once he fully recovered from surgery, but was unable to make a minor league appearance until July.

On July 22, 2010, Cordero agreed on a minor league deal with the New York Mets and was assigned to Triple A Buffalo.

On January 4, 2011, Cordero signed a minor league contract with an invite to spring training with the Toronto Blue Jays.