At Rice, Humber was coached by Wayne Graham. Humber's first home appearance at Reckling Park was in the annual Rice Alumni game in February 2002. After retiring his first two batters in relief, Humber faced a pair of Major League Baseball players. José Cruz, Jr. bounced the baseball off of the wall in center field and then Lance Berkman hit the ball over the scoreboard. After his inauspicious debut, he became a dominant pitcher during his three college seasons for the Rice Owls, stepping into the nationally ranked Owls' starting rotation as a freshman. Humber finished his freshman season in 2002 with an 11–1 win–loss record, a 2.78 ERA, and a WAC-leading 130 strikeouts in innings, earning National Freshman Player of the Year honors from "Collegiate Baseball" and All-America honors from several publications—"Collegiate Baseball" (Second Team), "Baseball America" (Second Team) and "Baseball Weekly" (Third Team). Humber's strikeout total was the most for an Owl freshman since 1976. That season, Rice reached the 2002 College World Series, but lost its first two games and was eliminated. Nonetheless, Humber earned an invitation to USA Baseball's national team trials. He was the scheduled starter in the second of the two games, which was against the Notre Dame Fighting Irish on June 17, but the team could not hold a 3–2 lead in the bottom of the ninth. He then competed for the United States national baseball team at the 2002 World University Baseball Championship, which was held in Messina, Sicily. On August 7, he earned a victory for the United States in a game against the South Korean team. The United States won the silver medal in the tournament.