Mazzone left the Braves after more than 15 years as pitching coach to take a lucrative, three-year deal with the Baltimore Orioles. During his tenure, Atlanta won 14 straight division titles and traditionally ranked among the top staffs in the National League.
"We are absolutely thrilled to add Roger to our staff,'' Braves manager Bobby Cox said. "Roger was a great competitor as a player -- he started, he relieved and he even fought through arm problems, so he comes in a with great level of experience that our pitchers will learn from.''
McDowell pitched in 723 games - mostly as a reliever - during a career that included stints with the Mets and Dodgers, along with the Philadelphia Phillies, Texas Rangers and Baltimore Orioles. He had a 70-70 record with 159 saves and a 3.30 ERA.
In 1986, McDowell was a member of New York's World Series-winning team. He went 14-9 with 22 saves in 75 games.
McDowell was pitching coach for the Class-A South Georgia Waves in 2002 and '03 in the Dodgers system.
"I have such strong respect for Bobby Cox and Braves general manager John Schuerholz,'' McDowell said. "They have built a very highly regarded organization and one that I am proud to represent. This is a very exciting time for my family, and I'm looking forward to meeting the challenges and expectations that are synonymous with Atlanta Braves baseball.''