Born in Padua, Tognon was a central midfielder who played for Milan during the 1940s and 1950s. Tognon played eleven seasons with Milan making 335 appearances preceded only by Gianni Rivera, Paolo Maldini, Franco Baresi, Billy Costacurta, Mauro Tassotti, Nils Liedholm and Cesare Maldini. He formed a tandem in midfield with Carlo Annovazzi. With Milan he won two championships, the first in 1951 having played 37 of 38 games, and the second in 1955 without playing any games; he served as the club's captain between 1953 and 1956. He later also spent a season with Pordenone before retiring in 1957.