Ruiz was born in Imperial, California; his parents had emigrated from Mexico to the US. His father is a former construction worker and started his own business flipping houses. There isn’t much information about his father.
Ruiz had a passion for baseball before his father got him into boxing, he noted that his first fight was at age 7 in San Diego. Ruiz after worked for his father in construction for a time before deciding to become a full-time boxer and starting his amateur career in Mexico.
His grandfather owned a boxing gym in Mexicali that was used by featherweight champion Jorge Paez.
Ruiz has explained that his nickname, Destroyer was acquired before he started boxing because as a child, “I was always destroying stuff”.