Selected in the seventh round of the 1953 NFL Draft out of Pittsburgh, Joe Schmidt came to the Motor City as an unheralded rookie with an incredible nose for the football. He quickly carved out a starting spot on a defense loaded with future Hall of Famers, making an immediate impact during Detroit's drive to the 1953 NFL Championship. By his second season, Schmidt had established himself as the absolute anchor of the Lions' defense, earning the first of ten consecutive Pro Bowl selections in 1954.

As head coach Buddy Parker installed the newly evolving 4-3 defense, Schmidt revolutionized the middle linebacker position. He brought unprecedented tactical instincts to the middle of the field, dropping seamlessly into pass coverage to blank opposing tight ends while maintaining the speed and instincts to fill run lanes from sideline to sideline. Named defensive captain in 1956—a leadership role he held for nine seasons—he essentially operated as an extension of the coaching staff, calling all defensive audibles at the line of scrimmage with uncanny accuracy.

Physically, Schmidt possessed a rare combination of brute strength and lateral range that set a brand-new prototype for the middle linebacker position. Listed at 6-foot-1 and 220 pounds, he was built like a granite slab, yet he maneuvered through traffic with the footwork of a safety. Rather than absorbing blocks from 250-pound guards, he used his fast hands and quick reads to slip underneath interior linemen, blowing up plays in the backfield before they could even materialize. His signature tackling form was devastating—a chest-to-chest blow that stopped ballcarriers in their tracks—and his sheer physical presence dictated how offenses approached the center of the field.

Schmidt reached the peak of his career in 1957, shining brightly as the defensive leader. He delivered an unforgettable season, with an impressive 157 tackles (80 solo) over 12 games, showcasing his talent and dedication. The United Press honored him with the NFL MVP award—an exceptional achievement for a defensive player—and he was also named to the First-Team All-Pro for the fourth year in a row. His remarkable season culminated in a spectacular performance during the 1957 NFL Championship Game, where he effectively contained rookie Jim Brown and the Cleveland Browns, helping Detroit secure a commanding 59–14 victory.

Opposing offenses really struggled to find an opening against him during his peak. When teams tried to throw over the middle, Schmidt would drop back into zone coverage with ease, grabbing 24 interceptions over his career. If they tried to run around the edges, his relentless energy and quick pursuit along the sidelines often forced runs out of bounds for only short gains. His knack for reading snap counts and spotting play-action fakes gave the Lions a clear strategic edge every time they took the field.

During his prime, Schmidt established one of the most impressive stretches by any NFL defender, earning eight First-Team All-Pro honors over nine seasons (1954–1957, 1958–1962). His strong leadership on defense made him a natural fit for coaching after retiring following the 1965 season. Schmidt joined the Lions' coaching staff as linebackers coach in 1966 and became head coach from 1967 to 1972, leading Detroit to four winning seasons and reaching the 1970 playoffs.

Schmidt played 13 seasons in Detroit (1953–1965), with 155 games, 24 interceptions, and 17 fumble recoveries as a top middle linebacker. He was named to the NFL 1950s All-Decade Team, had his No. 56 jersey retired by the Lions, and joined the Pride of the Lions in 2009. Inducted into the Pro Football Hall of Fame in 1973, he was also selected for the NFL 100th Anniversary All-Time Team.