Hlay was an All-State football player at Niles McKinley High School. He was heavily recruited by colleges, and narrowly chose Ohio State over Purdue University after Ohio State head coach Wes Fesler played on Hlay"s state loyalties.
As a sophomore Hlay lettered as a backup fullback and linebacker on the 1950 Ohio State team He suffered academic setbacks prior to his junior year, and incoming head coach Woody Hayes benched him for the first three games of the 1951 season.
When Hlay returned to the field in the fourth game of the season it was as a defensive replacement, playing exclusively as linebacker.
Hlay returned to the offensive backfield in his senior year, in part due to the support of backfield coach Doyt Perry.
As a senior Hlay led the Buckeyes in rushing, despite a backfield loaded with such talent as freshman Howard "Hopalong" Cassady, sophomore Bobby Watkins, and senior Fred Bruney. Hlay"s highest single-game rushing total was a 135 yard performance in a 21-14 loss to Purdue on October 4, 1952.