The team also promoted Kris Kline to director of scouting. Last year, Kline was the Nationals' assistant scouting director and national cross-checker.
"You are only as good as your lieutenants around you," general manager Mike Rizzo said. "We put together a staff of people who have strong baseball backgrounds and had great success. It's no coincidence the guys have championship rings.
"We are going to be judged by the results on the field, and it's good to have good baseball people around to help make the decisions."
Clark joins the Nationals after an 11-year run as director of scouting with the Braves. He joined the Braves as an area scout in 1989 and later enjoyed successive stints as Atlanta's southeast supervisor (1995) and national supervisor (1996 to 1999).
Clark's efforts helped the Braves earn Baseball America's prestigious Organization of the Year Award three times (1991, 1996, 2005) and USA Today's Organization of the Year citation in 1996. He owns a World Series ring from the Braves' 1995 championship team.
Clark is best known for having procured such talents as catcher Brian McCann, right-handers Kevin Millwood and Tommy Hanson, and shortstop Yunel Escobar.
Clark will assist on trades and help Kline with the 2010 First-Year Player Draft.
DiPuglia joins his fourth big league organization with this appointment. He spent the previous 10 seasons working in the Red Sox scouting department, the past four as Boston's Latin American scouting coordinator. While in that position, he was responsible for coverage in the Dominican Republic, Mexico, Curacao and Aruba, as well as all of Central and South America. He earned World Series rings with the Red Sox in 2004 and 2007.
DiPuglia, who also enjoyed stints with the Giants and Cardinals, signed or had a hand in the signings of shortstop Hanley Ramirez, second baseman Placido Polanco, outfielder Rick Ankiel and right-hander Anibal Sanchez.
Harris brings 20 seasons of baseball experience as a player, an amateur scout and a professional scout into his role with the Nationals. He spent last season as a Major League scout/advance scout with the Indians after a 12-year tenure with the Rangers in various scouting capacities. He played seven professional seasons for three organizations.
Harris, along with Bob Boone and Mark Scialabba, will oversee the farm system.
"It's really going to be a good marriage of baseball guys with great experience and real passion for the game of baseball," Rizzo said.
A scout for 20 seasons, Kline joined the Nationals in the fall of 2006 after spending the previous seven seasons with Arizona, the last three of which were spent as the D-backs' western supervisor.
Kline earned a World Series ring in 2001 when the D-backs topped the Yankees in seven games. Before joining Arizona, Kline worked 10 seasons scouting for the Angels after completing his four-year professional playing career.
The Nationals plan to add more front-office staff, for international scouting, and Rizzo wants to add another assistant GM who knows about contracts and baseball rules.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.