Green attended the University of Pittsburgh, where he played defensive end for the University of Pittsburgh Panthers from 1977 to 1980. Green was part of an elite team that included three future NFL Hall of Fame players: Defensive end Rickey Jackson, Center Russ Grimm, and quarterback Dan Marino. Several other future NFL stars would be his teammates, including Mark May and Jimbo Covert. He was a three-time consensus first-team All-American (1978, 1979, 1980) and a second-team All-America selection as a freshman in 1977. He was a consensus four-time All-East selection as well. In the 4 years Green played, the Pittsburgh Panthers compiled a 39–8–1 record, winning three bowl games en route (two Gator Bowls and one Fiesta Bowl). His No. 99 jersey was retired at halftime of his final home game in the 1980 season. After the season, he played in both the Hula Bowl and Japan Bowl All-star games.