Herbert Jefferis Pennock (February 10, 1894 – January 30, 1948) was an American professional baseball pitcher and front-office executive.

He played in Major League Baseball from 1912 through 1933, and is best known for his time spent with the star-studded New York Yankee teams of the mid to late 1920s and early 1930s.

After retiring as a player, Pennock served as a coach and farm system director for the Red Sox, and as general manager of the Philadelphia Phillies.

After struggling as a first baseman, with weak offense and a inability to throw the ball straight, Pennock was converted by his Cedarcroft coach into a pitcher.

Pennock threw a no-hitter against a traveling Negro league baseball team, and Mack promoted him to the Athletics.

[1] Mack intended for Pennock to be one of the prospects who would replace star pitchers Eddie Plank, Chief Bender, and Jack Coombs.

[8] With a deep pitching staff in place, the Red Sox loaned Pennock to the Providence Grays of the International League in August for the remainder of the 1915 season.

After the game, Ed Barrow, the new manager of the Red Sox, signed Pennock to a new contract after promising to use him regularly during the 1919 season.

[15] The Yankees traded Norm McMillan, George Murray, and Camp Skinner to the Red Sox for Pennock that offseason.

[25] After pitching a three-hit shutout against the Red Sox on August 12, 1928, he missed the remainder of the season, including the 1928 World Series, with an arm injury.

His five shutouts and 0.085 home runs per nine innings pitched led the AL. His 2.56 ERA trailed only Garland Braxton, while his 17 wins tied for eighth place.

[1][32] Eddie Collins, a former teammate with the Athletics now serving as the general manager of the Red Sox, signed Pennock to their 1934 roster.

[1][8] Pennock became the general manager of the Charlotte Hornets, a Red Sox' farm team of the Piedmont League, prior to the 1935 season.

[1][37] In December 1943, R. R. M. Carpenter Jr., the new owner of the Philadelphia Phillies, hired Pennock as his general manager,[38] after receiving a recommendation from Mack.

Pennock filled Carpenter's duties when the team's owner was drafted into service during World War II in 1944.

As general manager, Pennock changed the team's name to the "Blue Jays"—a temporary measure abandoned after the 1949 season—and invested $1 million ($17,308,129 in current dollar terms) into players who would become known as the "Whiz Kids", who won the National League pennant in 1950, including Curt Simmons and Willie Jones.

[1] He also created a "Grandstand Managers Club", the first in baseball history, allowing fans to give feedback to the team,[39] and advocated for the repeal of the Bonus Rule.

The only source of the story about the call to Rickey was from the 1976 book The Lords of Baseball by Harold Parrott who claimed to have listened in on the conversation on an extension line, something which didn't exist at the time.

[45] Additionally in his book, Craig mentioned that Pennock and his wife took in a black woman who had fled an abusive husband in the 1930s, lived with their family for the rest of her life and was buried next to him.

[44] In 1948, at the age of 53, one week and four days before his 54th birthday, Pennock collapsed in the lobby of the Waldorf-Astoria Hotel as a result of a cerebral hemorrhage.

[46] Pennock had appeared to be in good health, even inviting friends to join him at Madison Square Garden to attend a boxing match, prior to being stricken.

[48] In 1998, an attempt to erect a statue in Kennett Square in his honor was blocked due to his support of segregation in baseball.

[49] In 1981, Lawrence Ritter and Donald Honig included Pennock in their book The 100 Greatest Baseball Players of All Time.