John Avery Haldeman (December 2, 1855–September 17, 1899) was a journalist who played one game for Major League Baseball's Louisville Grays in the 1877 season.

[4] The Grays were having an excellent season until a seven-game losing streak in late August, prompting Haldeman to write a column in the Courier-Journal questioning the reason for the team's slide.

[5] The poor play continued on a road trip later in the season, causing the team to fall out of first place in the league and lose the pennant race.

[2] This prompted Haldeman to question the performance of players such as pitcher Jim Devlin, who he claimed had not used his best pitch during the entire road trip.

[2] Haldeman's accusations eventually gained traction, and four players – Devlin, Craver, Al Nichols, and George Hall – were found to have thrown games.