Vallera had a variety of support duties, including aiding in communication with Latin players.
Young, who played 15 years in the majors, was on manager Kirk Gibson's staff for two years. His duties included baserunning and outfield defense. The Diamondbacks were caught stealing 51 times, second worst in the majors behind Pittsburgh (52).
Gibson and general manager Kevin Towers said in a conference call Wednesday that the team would add a new coaching position to work under hitting coach Don Baylor.