The new position was successful; he became an important figure in the team's strong defence, and indirectly set examples for teammates Tarcisio Burgnich and Giacinto Facchetti with his leadership.

Picchi made his debut for Italy several months after becoming Intercontinental champion with Inter Milan, in a 6–1 victory over Finland in November 1964.

However, Italy coach at that time, Edmondo Fabbri, deemed him unsuitable for the team's scheme, as he felt he was too defensive minded, and subsequently left him out of the squad for 1966 World Cup in England.

[4] A quick, versatile and tenacious defender, Picchi began his career playing as a forward or as a central defensive midfielder, before being moved to right back, where he excelled, but later came into his own in the libero role.

Picchi was primarily an old-fashioned sweeper, who was mainly known for his defensive skills, strong physique, and ability to win back, intercept and clear loose balls as a last man, while he was not particularly good in the air, due to his small stature; despite his more traditional, defensive-minded interpretation of the role, he was, however, also occasionally capable of getting forward, and of carrying the ball out into midfield, or starting plays from the back-line, due to his good technique and ability to read the game.