He played his entire career in Major League Baseball as a right-handed pitcher for the Cincinnati Reds from 1974 through 1976.

Signed as an amateur free agent in 1969 by the Houston Astros, Darcy came to the Cincinnati Reds organization in 1974 when he was exchanged for Denis Menke.

Darcy is best known as the pitcher who gave up Carlton Fisk's walk-off home run in Game 6 of the 1975 World Series.

The following season, after recording a 6.23 ERA in 11 appearances with the Reds, Darcy was demoted to the team's Indianapolis Indians farm club in June of that year.

[1] Darcy returned to Tucson after his major league career, earning his degree at the University of Arizona, starting his family, becoming active in the real estate industry and various aspects of local civic life.