From Glendale, Kentucky, Hagan played for Tennessee Tech from 1957 to 1960. While there, the 6 ft 10 in (2.08 m) center became one of the best players in program history. The slender big man was known as a prolific scorer with a deft shooting touch, particularly from the free throw line.[1][2] In his junior season, Hagan used his offensive skill very effectively in coach John Oldham's high post offense. Hagan averaged 28.8 points per game and engaged in a highly publicized national scoring race with eventual scoring leader Oscar Robertson.[3][4] At the close of the season, Hagan was named first-team All-Ohio Valley Conference and a third-team All-American by the Associated Press.[5]
In his senior season, Hagan's scoring average dipped to 24.3 points per game. He was again named All-OVC and was the only unanimous choice for the squad.[6] Hagan left Tennessee Tech holding a number of records - including total career points (1,539, since eclipsed), total career rebounds (1,108), season scoring average (28.8 points per game in 1958–59) and career scoring average (21.1 points per game). He was inducted into the Tennessee Tech athletic Hall of Fame in 1979 and his jersey has been retired by the school.[7]