I recently visited the Pro Football Hall of Fame in Canton, Ohio and was reminded as I walked through the hall of bronze heads of just how many Packers have made an indelible mark in league history. 24 men are enshrined, second only (for the time being) to the Chicago Bears.

Of those two dozen Packers, one of the more forgotten names is tackle Robert “Cal” Hubbard. A charter member of the Hall of Fame, Hubbard played both offense and defense for Green Bay. His massive size for the time – 6-foot-2, 253 pounds – puts him physically between linebackers Jake Ryan and Jayrone Elliott on today’s roster.

Hubbard anchored the left tackle position on offense – by comparison, current Packers left tackle David Bakhtiari is 6-foot-4, 310 pounds – and played on the other side of the ball as an interior defensive lineman. When the NFL began naming All-Pro players at each position in 1931, Hubbard made the inaugural list with a position of tackle.

Because professional football was not considered a high-paying career in the 20’s and 30’s, Hubbard spent his offseason as a minor league baseball umpire. After his playing days in football ended in 1936, Hubbard began a career as an American League umpire that spanned from 1936-1951 and a supervisor for officiating crews until 1969. 

Hubbard was a top-flight umpire. Just two years after beginning his American League career, he was selected as an umpire for the 1938 World Series. In a time when umpires' organization on the field was haphazard, Hubbard defined and simplified each umpire's duties and provided the foundation for Major League Baseball's officiating standards that were published in 1952.

A year before his death in 1976, Hubbard was inducted as an umpire to the National Baseball Hall of Fame in Cooperstown, New York. To this day, Hubbard remains the only man in both football and baseball’s hall of fames.