text: Major league career Nelson made his major league debut with the Mariners on April 16, 1992, against the Chicago White Sox at Comiskey Park. He pitched two scoreless innings of relief.
  On July 13, 1995, Nelson entered a game against the Toronto Blue Jays with two runners on base and no outs. Nelson threw one pitch to Sandy Martínez and induced a ground ball triple play. He became the first pitcher in the era for which pitch count data is available to throw only one pitch in an outing and be credited with pitching a full inning.
  In December 1995, the Mariners traded Nelson, Tino Martinez, and Jim Mecir to the New York Yankees for Russ Davis and Sterling Hitchcock. With the Yankees, Nelson was a member of the World Series champions in 1996, 1998, 1999, and 2000.
  Nelson returned to Seattle as a free agent in . In that season he made the American League All-Star team. Nelson's All-Star selection was considered an innovative move by AL manager Joe Torre, as Nelson's role of middle relief was traditionally overlooked during All-Star selection.
  From 2001 to 2003, he formed the right side of Seattle's potent lefty/righty setup squad along with left-handed pitcher Arthur Rhodes. In 2001, he held opposing batters to a .136 batting average and a .199 slugging percentage, and .074/.110 once he had two strikes on them.