The Arizona Diamondbacks named Josh Byrnes as their senior vice president and general manager on Friday. Byrnes, who received a four-year contract with a club option for a fifth season, had been assistant to Boston Red Sox general manager Theo Epstein since 2002. "We are thrilled to have Josh join our staff," said Diamondbacks managing general partner Ken Kendrick. "He has a tremendous amount of knowledge, energy and experience, and is obviously prepared for this opportunity. He understands our commitment to bringing a championship team back to our fans and we are confident that he has the skills and abilities to guide us there." The 35-year-old Byrnes takes over for Joe Garagiola Jr., who resigned from the post to become senior vice president in the commissioner's office. Byrnes is the second full-time GM in Diamondback history, following Garagiola, who held the position from 1995 through July of this year. Bob Gebhard had served as the interim GM since Garagiola's departure. "We feel strongly about this direction," said Diamondbacks general partner Jeff Moorad. "This is a significant move in our focus on strengthening all aspects of our baseball operations. Josh has been associated with winning teams and successful general managers throughout his career that have helped shape his impressive vision." Before joining the front office in Boston, Byrnes was scouting director of the Cleveland Indians and assistant GM