Born in Nueva Helvecia, southern Uruguay, Franco Israel took his first steps at Club Lucerna, where he joined at the age of nine. At this age he was passionate about football but, at the same time, showed aptitude for basketball. In the ended he opted to become a goalkeeper. He continued his football career at Club Artesano, until Nacional signed him in 2016, culminating in the conquest of the under-20 Libertadores Cup. That success led to Juventus signing him, having played, in recent seasons, for the Bianconeri's B team, although with regular call-ups to the first squad.

Signed by Sporting CP until 2027, Franco Israel is an international for the Uruguayan youth teams and has even rejected a call to the Italian Olympic team, revealing his desire to play at the highest level for his country. As a new Lion, he said he was looking forward to working with his teammates and making his debut for Sporting.