He returned to Milan in 1990, where he was a reserve in the first team's defence, behind the legendary Maldini, Baresi, Costacurta, Tassotti back-line, which is regarded by many as the sport as one of the greatest defensive line-ups of all time. He made his Milan debut on 5 September 1990, in a 1–0 home Coppa Italia victory over Triestina, as Milan went on to reach the final of the tournament. He made his Serie A debut with the club on 3 March 1991, in a 4–1 home win over Napoli. In his four non-consecutive seasons with Milan (1990–91 under Arrigo Sacchi, and 1992–995 under Fabio Capello), Nava made a total of 47 appearances in all competitions, and 21 Serie A league appearances, scoring 1 goal, which came in Serie A. During his time at the club he won two Serie A titles, three Supercoppa Italiana titles, two UEFA Super Cups, an UEFA Champions League, and an Intercontinental Cup. He spent the 1991–92 season only loan with Parma, where he won the Coppa Italia. His final appearance with Milan was in a 5–0 away victory against Brescia, during the 1994–95 Serie A season, on 5 March 1995.