He was raised Jewish, and has said: "People are shocked at first that I’m Jewish. I wished I had been out playing baseball, but looking back at it now, I’m happy I did it.”In 1996, Valencia pitched for the Boca Raton Babe Ruth League 12-and-under all-star baseball team that won the Florida state championship.
I get teased in the clubhouse about being Jewish, but we all get teased about something. The next year, he pitched and hit for the Boca Lightning 12-and-under travel baseball team that went 27–2 and won the South Florida All-Star Travel League championship.
Immediately following the All Star game, he was promoted to the high A Fort Myers Miracle.
He earned Florida State League (FSL) "Player of the Week" honors, batting .379 (11–29) with two home runs, three runs scored, and 10 RBIs for the week of July 16.
Homesick for Florida, Valencia sought to transfer to the University of Miami after his freshman year, even though it only offered him a modest scholarship.