Much travelled, his clubs included the New York Giants (1952-56), Baltimore Orioles (1958-62), Chicago White Sox (1963-68), and spells with the St. Louis Cardinals, Cleveland Indians, California Angels, Atlanta Braves, Chicago Cubs and Los Angeles Dodgers, with whom he was playing when he eventually retired after the 1972 season.

His success as a reliever helped the gradual change in usage patterns of pitchers, and the popularity of the concept of a "relief ace". Along with Phil Niekro, Wilhelm is considered by many one of the greatest knuckleballers to have played the game, and he was elected to the Baseball Hall of Fame in 1985.

The highlight of Wilhelm’s career came at a time when his career was in flux. The first six years in the majors, Wilhelm appeared in 361 games, all in relief. But in 1958, Cleveland manager Bobby Bragan used him occasionally as a starter, and Wilhelm continued in that dual role after a mid-season trade to Baltimore. On September 20, sporting a 2-10 won-lost record, he got the start against the New York Yankees, who had already clinched the American League pennant. The opposing pitcher was Don Larsen, who two years earlier had thrown a perfect game in the World Series. On this drizzly evening, Wilhelm fashioned his own gem, striking out eight and throwing the only no-hitter of his career against the soon-to-be World Series champs.

Although his accomplishments as a pitcher are well known, Wilhelm also holds an interesting record as a batter. On April 23, 1952, in his second game with the New York Giants, Wilhelm came to the plate for the first time in the majors. Facing rookie Dick Hoover of the Boston Braves, Wilhelm swung and sliced a home run over the short right-field fence at Ebbets Field. Although he played 21 seasons and went to bat a total of 432 times in his career, he never hit another home run.

Career statistics