After growing up in Magnolia, TX, Dugger played his first two years of college baseball at Cisco Junior college. He finished 8-7 in his career, with an ERA of 4.88. In his sophomore season, he had a K:BB ratio of 55:18 in 70 innings. After his time in JUCO, Dugger went to Texas Tech where he played one season before being drafted by the Mariners.
In his lone season at Texas Tech, he pitched as a reliever, accruing 60.2 innings in 30 appearances. He posted an ERA of 2.67. His K:BB ratio at Texas Tech was again solid at 54:23.