Securing a genuine defensive cornerstone in the 18th round of the NFL Draft is extremely rare, but in 1963, the St. Louis Cardinals achieved this by choosing Georgia Tech’s Larry Stallings as the 241st pick overall. Despite never playing linebacker in college, Stallings was inserted into the starting lineup as a rookie and rapidly adapted, holding the left outside linebacker position for fourteen seasons straight (1963–1976).

Stallings applied a tough, blue-collar mentality to the second level of the Big Red defense. He excelled at setting the edge against the run, strongly resisting being pushed out by pulling guards, and had the agility to drop into boundary coverage. Despite facing early-career knee surgeries in 1964 and 1965, Stallings returned as a full-time starter in 1966 and demonstrated remarkable durability. From 1966 until the end of his career, he played all but two games over an eleven-year period.

His consistent performance earned him early recognition from his teammates, who named him the Cardinals Team MVP after the 1969 season. Stallings hit his career peak in 1970, achieving his best season with 4.0 sacks, two fumble recoveries, an interception, and earning First-Team All-NFC honors from UPI, along with his first Pro Bowl selection. From 1966 to 1976, Stallings was a mainstay at left linebacker, starting 149 of 151 regular-season games.

Stallings served as the defensive team's core through the mid-1970s, offering veteran leadership for the back-to-back NFC East division champions under Don Coryell in 1974 and 1975. When he retired after the 1976 season, he had played all 181 games with the Cardinals, starting 175 of them, and recording 9 interceptions, 13 fumble recoveries, 3 defensive touchdowns, and 27.5 unofficial sacks.

He retired following the 1976 season, finishing with 9 interceptions, 13 fumble recoveries, and 3 defensive touchdowns.