He played for 17 seasons as a catcher in Major League Baseball (MLB) from 1941 to 1942 and 1946 to 1960, most notably for the Cleveland Indians with whom he won a World Series in 1948.

Although Hegan was a light-hitter as a player, he earned acclaim within the game (amongst both peers and journalists) as one of the best defensive catchers of his era and a capable handler of pitching staffs.

[4] Hegan appeared in 68 games for the Indians in 1942, before joining the United States Coast Guard for the remainder of the Second World War.

In his second season back after the war, Hegan was recognized as one of the top catchers in the American League when, he was selected as a reserve in the 1947 All-Star Game.

[11][12] Hegan's pitch-calling skills continued to be made evident as, the Indian's pitching staff would lead the American League in earned run average every year from 1948 to 1951.

[1][17] Cleveland Indian Hall of Fame pitcher Bob Feller was quoted as saying,"He was one of the best defensive catchers in baseball history.

[26] As a testament to Hegan's pitch-calling skills during this period, the Indians' pitching staff was the best in baseball, leading the American League six times in earned run average.

[28] Despite his considerable defensive skills, because he was a light-hitting player, Hegan is almost a forgotten man in major league baseball history.

In mid-year, after his active career ended July 4, Hegan became the full-time bullpen coach for the New York Yankees, helping to mentor future catching stand outs Thurman Munson and Rick Dempsey.