Joined by legendary head coach Paul Brown in 1946 after serving in the U.S. Army during World War II, Frank Gatski earned a spot on the inaugural Cleveland Browns through a walk-on tryout. Over 11 seasons in Cleveland, "Gunner" anchored the offensive line with relentless consistency and mistake-free mechanics, serving as the unsung offensive centerpiece for one of the greatest dynasties in pro football history.

Gatski drew on physical strength from his West Virginia coal-mining roots, leverage, and perfect mechanics. As the starting center, he ensured Otto Graham never experienced a botched exchange. His ability to snap, step, and instantly wall off interior nose tackles allowed Cleveland's trap-draw run scheme with Marion Motley to flourish, while his sturdy base kept the interior pocket clean against heavy blitzes.

Gatski became the Browns' full-time starting center in 1948 after two years backing up Mo Scarry. He led the line for an offense that secured all four AAFC Championships from 1946 to 1949, including a perfect 15–0 record in 1948. When the team transitioned to the NFL in 1950, Gatski continued to excel, starting every game as Cleveland won the 1950 NFL Championship in its first season.

His exceptional skills led to consecutive NFL Championship wins in 1954 and 1955. Widely regarded as the premier center of his era, Gatski received three first-team All-Pro honors (1952, 1953, 1955) and was selected for the Pro Bowl in 1956. Throughout his 12-year career, he appeared in 11 championship games, securing seven titles with Cleveland and adding an eighth after his trade to the Detroit Lions in 1957.

Gatski, renowned for his exceptional durability, supposedly never missed a practice or game during his high school, college, or 12-year professional football career. His achievements were cemented with his induction into the Pro Football Hall of Fame in 1985. Additionally, in 2010, the Cleveland Browns permanently honored him by inducting him into the first class of their Ring of Honor.