Diego Simeone
Among speculation of Atlético Madrid's interest in signing the young player to be coached by his father Diego Simeone, Giovanni signed with Serie A club Fiorentina on August 16, 2017 for an undisclosed fee. On April 29, 2018, Simeone completed his first hat-trick in Serie A in Fiorentina's 3–0 win against Napoli.