Nava began his career in 1985 with Pro Sesto, before joining the Milan Youth Squad. In 1988, he made his professional debut in Serie C1 with Virescit Boccaleone, and during the next season, he moved to Serie B side Reggiana. 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, 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. Nava took part in the Milan's 4–0 win over FC Barcelona in the 1993–94 Champions League final on 18 May 1994, alongside usual substitutes Christian Panucci and Filippo Galli, entering as substitute in the 84th minute of the match replacing Paolo Maldini. After his time with Milan, Nava spent a season on loan at Padova, and another with Servette in Switzerland, the club to which he later moved on a free transfer. He subsequently spend two seasons with Sampdoria before ending his career with Pro Sesto in Serie C2, at the conclusion of the 2000–01 season.
After retirement
Nava had a one-month spell as Pro Sesto head coach in January 2004, the team with which he began his career, and eventually retired. He later became the coach of Masseroni Marchese, helping with the Milan Youth Programme. During the 2011–12 season, he became the coach of the Milan Giovanissimi Nazionali Youth squad, and the following season, he worked alongside Filippo Inzaghi, who was the coach of the Milan Allievi Nazionali Youth Side. During the 2014–15 season, he was appointed the coach of the Milan Berretti Youth Side. He currently works as a football commentator and pundit for SKY Italia. In 2014, he was named as the new analyst for the Italian edition of EA Sports' FIFA 15, alongside match commentator Pierluigi Pardo, replacing Giuseppe Bergomi.
