DiGregorio played on the 1968 Rhode Island (Class B) champions at North Providence High School. He and Marvin Barnes led Coach Dave Gavitt’s Providence team to a Final Four appearance in the 1973 NCAA Tournament in DiGregorio’s senior season, where they eventually lost to Memphis State, but only after Barnes sustained a knee injury that forced an early exit. After playing for the Providence College Friars, DiGregorio played on a college all-star team, and along with Bill Walton, led the U.S. in defeating a Soviet team in an exhibition game, which helped heal the still-open wound of the United States’ loss in the 1972 Summer Olympic finals. Ernie “D” was then drafted by the Kentucky Colonels of the American Basketball Association but opted instead for the NBA.