Nicknamed La Diga ('The Dam') for his qualities as a defensive midfielder,[2] Ferrini played for Torino from 1959 to 1975, and is the most capped player in the history of the Granata with 566 appearances in all competitions, ahead of Paolo Pulici (437).

The following season he was confirmed as a key player for Torino by the manager Benjamín Santos, and debuted in Serie A on 25 September 1960 in a loss to Sampdoria (0–1).

[4] He was summoned by the national team manager Gipo Viani to represent the Azzurri, who finished in fourth place at the Olympic tournament held in Rome in 1960,[5] playing three times.

[4] Also in 1960, he was called up to the Nazionale di Lega della Serie A under-23 against the homologous team of the English League, which he entered in the 30th minute, replacing Giacomo Bulgarelli.

[7] A hard-working, aggressive, and energetic wide midfielder of quantity, Ferrini was known for his stamina and his hard challenges, as well as his dedication, consistency, and leadership, despite his lack of notable technical ability.

[3][4][8][9] A few months after his retirement, while he served as assistant coach of Luigi Radice in the season in which Torino returned to win the Serie A title, he suffered two aneurysms (25 August and, after an initial recovery, 18 October 1976).