The native of Knoxville, Tennessee, was a right-handed relief pitcher who appeared in 161 games over six seasons (1967–1972) for the Houston Astros, San Diego Padres, Baltimore Orioles and California Angels of Major League Baseball.

Dukes signed with the New York Yankees in 1960 but never appeared for the Bombers, who traded him to the Milwaukee Braves for veteran reliever Bobby Tiefenauer in June 1965.

In August 1967 he finally made the majors in his eighth pro season, and he pitched out of the Houston bullpen through the end of 1968, working in 60 games and notching six saves.

He was traded along with Pat Dobson to the defending World Series Champion Orioles for Enzo Hernández, Tom Phoebus, Fred Beene and Al Severinsen on December 1, 1970.

Baltimore breezed to its third consecutive American League championship, but fell to the Pittsburgh Pirates in the 1971 World Series; Dukes worked in Games 3 and 5 and allowed no runs and two hits in four innings pitched, with one strikeout.