Why Bilbao Athletic players are called "cachorros"?

San Mamés, his Christian faith and the Roman circus in which he was thrown to the lions are to blame for Bilbao Athletic nickname, the second team of Athletic Club. Younger players of the “rojiblanco” club are called “cachorros” (cubs) because they are considered the little brothers of the first team players, which are known as “leones” (lions). 

Los cachorros de Ziganda ya están preparados para el choque ante el Cádiz #lezama pic.twitter.com/JEXlUwSnMA

— Athletic Club (@AthleticClub) June 26, 2015

The origin of this story goes back to the third century, when Mamés, one of the most popular saints, was arrested and stripped of all his goods in Caesarea of Cappadocia, for not to renounce to his faith. Mamés was thrown to the lions, but far for devoured him, the lions lay right on his feet in sign to praise. 

When, after construction, the stadium was renamed with the name of the saint  to honored  the most popular shrine in  Bilbao city, players and everything related to Athletic was associated with lions, animals saved from San Mamés. Hence, the small ones of the club, also they have kept the nickname of "cachorros".