 After attracting attention from larger clubs, he joined Juventus in 1993 for 11 billion Lit., featuring as a starter during the 1993–94 season under manager Giovanni Trapattoni.During the 1994–95 season, however, he had difficulty finding a place in the team's starting line-up under the club's new manager Marcello Lippi; due to Lippi's new three-man back-line, Porrini faced heavy competition from other defenders, such as Moreno Torricelli, and Jürgen Kohler, as well as back-up Massimo Carrera.In particular, Porrini was kept out of the starting eleven by the newly acquired Ciro Ferrara, whom Lippi had even moved onto the right flank in order to accommodate him into the team's new back-line.