In the beginning of his sophomore year in 1966, Jackson replaced Rick Monday (the first player ever selected in the Major League Baseball draft and a future teammate with the A's) at center field. He broke the team record for most home runs in a single season, led the team in numerous other categories and was first team All-American. Many scouts were looking at him play, including Tom Greenwade of the New York Yankees (who discovered Mickey Mantle), and Danny Murtaugh of the Pittsburgh Pirates. In his final game at Arizona State, he showed his potential by being only a triple away from hitting for the cycle, making a sliding catch, and having an assist at home plate. Jackson was the first college player to hit a home run out of Phoenix Municipal Stadium.