 Nixon remained in the game as a minor-league manager and instructor, except for , when he returned to the American League to spend one year as a coach for the Seattle Mariners.At age 70, he spent the 2005 season as manager of the Greeneville Astros, rookie-level Appalachian League affiliate of the Houston Astros, and in 2006–07 he was a roving instructor in the Houston farm system.In 2008, Nixon, then 73, was still active in baseball as a roving instructor in the Texas Rangers' farm system, appointed by the club president at the time, Nolan Ryan.