The team said Hickey died Wednesday at Rush University Medical Center in Chicago. He had been in intensive care following his transfer from a Dallas hospital last month after missing the team's workout before Opening Day. A cause of death was not disclosed.
Hickey, a left-hander, pitched with the White Sox from 1981-83 and the Orioles from 1989-91, compiling a 9-14 record, 3.91 ERA and 17 saves in 231 relief appearances.
A Chicago native, Hickey didn't play high school baseball. But after competing in 16-inch softball and semipro baseball, he was invited to a Comiskey Park tryout and offered a minor-league contract. He pitched three minor league seasons before making his major league debut.
He had been the White Sox's pre-game instructor since 2004.