There's not much information available about of his personal life or his beginnings in before he became a pro. In fact, there's some discrepancy about the exact date of his debut. Some sources indicates he became Pro in 1926, other sources indicates his pro debut was July 25, 1930, but officially, it is recorded at 1932. The "San Antonio Express" reported in 1944 that Villanueva's passport's birth date was June 21, 1917, and not June 21, 1913. If this is true, he was only 13 when started his career.