One day after football practice, he approached ASU baseball coach Bobby Winkles and asked if he could join the team. Winkles said he would give Jackson a look, and the next day while still in his football gear, he hit a home run on the second pitch he saw; in five at bats he hit three home runs. He was allowed to practice with the team, but could not join the squad because the NCAA had a rule forbidding the use of freshman players. Jackson switched permanently to baseball following his freshman year, as he did not want to become a defensive back. To hone his skills, Winkles assigned him to a Baltimore Orioles-affiliated amateur team. He broke numerous team records for the squad, and the Orioles offered him a $50,000 signing bonus if he joined the team. Jackson declined the offer stating that he did not want to forfeit his college scholarship.