Warwick batted right-handed but threw left-handed; he stood tall and weighed . Born in Dallas, Texas, he graduated from Sunset High School and then played varsity baseball for Texas Christian University, leaving after his junior season to sign a bonus contract with the Dodgers. In his second pro season, 1959 with the Victoria Rosebuds, he led the Double-A Texas League in runs scored (129) and home runs (35), hit .331 and was selected Most Valuable Player. The following year, playing with the Triple-A St. Paul Saints, he was named an American Association all-star.