July 17, 2007 Don started his major league career with the Yankees in 1934, spending four seasons in the Bronx as a utility player. He was traded to the St. Louis Browns before the 1938 season and was a regular in St. Louis for four seasons, mainly at second base and sometimes at shortstop. He also had brief stops with the Philadelphia A's and Detroit Tigers.
Heffner was a successful minor league manager for about ten years starting in 1947, then joined the Kansas City A's as a coach in 1958. He moved to Detroit as a coach in 1961, then went back to managing in the minors the next two seasons. Don was hired by the Mets and was their third base coach in 1964 and 1965.
Right after the 1965 season, having seen Wes Westrum succeed Casey Stengel, Don accepted the managerial job with the Cincinnati Reds. The 1966 season was the first season for the Reds after they had traded Frank Robinson to Baltimore for Milt Pappas. The Reds stumbled along through the first half of the season, and Heffner was fired at the All-Star break with a record of 37-46. It was to be his only taste of managing in the majors.