He was an example of a trend of the young league to draft players from small colleges, which was deemed innovative in part due to its results that it cultivated, which Sestak represented well.
Sestak was a starter in his rookie year and, until a series of knee injuries ended his career after the 1967 season, used his strength to dominate the line of scrimmage.
Over the 1964 and 1965 seasons, Sestak and his defense mates held opposing rushers without a touchdown for seventeen consecutive games, a Professional Football record that still stands.
He notably played a season with three broken ribs, and his knees problems meant that he spent time at a stationary bicycle instead of scrimmage during practice.
During the 1960s, only six professional defensive linemen were unanimous All-League selections for three or more years, Sestak (3), Bob Lily (5), Merlin Olsen (4), Willie Davis (3), Gino Marchetti (3), and Deacon Jones (3).