He often got more attention for his handsome looks, flashy dress, gold jewelry, flamboyant behavior, and his personal life rather than for his ball playing.

[5][6] McDuffie started his baseball career in 1930 as an outfielder for the Birmingham Black Barons, hitting a .297 batting average with a .353 on-base percentage and leading the Negro leagues with 18 stolen bases.

[7] He frequently changed teams between 1932 and 1933, including stints with the Atlantic City Bacharach Giants, Pollock's Cuban Stars, Hilldale Daisies, and Baltimore Black Sox before joining the Pennsylvania Red Caps of New York in 1934.

In that season, he pitched an 18-inning, 3–1 victory over the Jacksonville Red Caps and hurled a no-hitter for the Brooklyn Eagles against the House of David club the next year.

[11] After that, McDuffie spent 1939 with the Black Yankees and the Baltimore Elite Giants and made his first appearance in the East-West All-Star Game in a relief role.

McDuffie led the league's pitchers with a 5–3 record, surpassing Johnny Lindell, Bob Feller, Lee Stine, George Darrow, Tom Glover, and Pat Tobin, among others.

Once the enraged manager returned to the locker room from his adjacent office waving a loaded pistol and pointing it at the pitcher, McDuffie quickly changed his mind, went out and fired a two-hitter game.

He played for the Senadores de San Juan in the 1941–1942 tournament, joining a team that featured Monte Irvin, Luis Olmo and Bill Wright.

He reported late for his first stint with Magallanes, but posted a 3–0 record and a solid 1.86 ERA in four pitching appearances, including three starts and two complete games, helping the team win the pennant.

[23][24] The Venezuelan club finished with a 1–5 record in the Series, while McDuffie lost his two starts against Luis Arroyo and the Criollos de Caguas by scores of 2–1 and 3–2, suggesting a bit of bad luck.

In his first start McDuffie was blanking the Puerto Rico team 1–0 on three hits through eight-plus innings, but gave up a two-out, pinch-hit two-run homer to Wilmer Fields in the bottom of the ninth, and Caguas won the contest 2–1.

He posted a 14–3 record in the regular season and went 2–0 with a save in the playoffs, as the Aguilas Cibaeñas defeated the Tigres del Licey in the maximum of seven games to claim the championship title.

[26] At age 44, he had the last run in the Texas League with the Dallas Steers club in 1954, posting a 3–4 record and a 3.04 ERA in 14 games (nine starts).

[3] In 2007, he received the honor of induction into the Cuban Baseball Hall of Fame based in Miami, as part of their Phase IV.