[3] He was North Mecklenberg's second NFL alumni and was a two-way player for the school, being a linebacker on defense while on offense a guard.
[3][4] He was regarded as one of the best linebackers in his county in the 1966 season and was co-team captain, being named The Charlotte News All-State and All-Mecklenberg.
[8][9] He returned as a starter for his junior year in 1970; that season, he weighed at 208 pounds (94 kg) and ran the 40-yard dash in 5.0 seconds.
[2] He was a top player for the team that year, being described by The News & Observer as the "anvil" of the defense; the paper noted that he "jars running backs with some Dick Butkus-like jolts.
[17][18] He returned to playing middle linebacker in the 1973 season and served as a backup to Jim Carter, appearing in 14 games while posting one interception and a fumble recovery as the Packers went 5–7–2.
[1][19][20] In 1974, Hefner played all 14 games, one as a starter, and helped the Packers compile a record of 6–8 while recovering one fumble and returning one punt.