Major league career

Walker's big break came in 2005, when Giants' closer Armando Benítez was out of action for three months. With only one major league save in his career to that point, Walker filled in admirably by converting 23 out of 28 save opportunities. On June 17, in a game against the Detroit Tigers, Walker made history by becoming the first pitcher to record a save (since the save rule became an official stat in 1969) by entering a game with the bases loaded with nobody out and proceeding to strike out all three batters he faced without allowing a run to score.

Early in the 2006 season, Walker was sent to the Tampa Bay Devil Rays in exchange for minor leaguer Carlos Hines. On June 14 of that year, he was placed on the disabled list with a strained right elbow, and later underwent season-ending Tommy John surgery. On December 10, 2006, he signed a minor league deal with the Giants. He pitched in 15 games late in the 2007 season and re-signed with the Giants for 2008. In 65 games in 2008, he had a 4.56 ERA and became a free agent after the season. On January 6, 2009, he signed a one-yeal deal with the Seattle Mariners. He was released on March 29, 2009, before the start of the regular season. After that, he was signed by the Phillies on April 9, 2009.

On January 25, 2010, Walker agreed to a one year contract with the Washington Nationals. He posted a 3.57 ERA during the 2010 season out of a long relief role. After the season ended, he became a free agent.

Walker signed with the Long Island Ducks of the Atlantic League on September 14, 2011.

[ Source: Wikipedia ]