The Player of the Month Award could be given to a pitcher in the National League between 1958 and 1975 (see Fast Fact #2) or in the American League (see Fast Fact #3) between 1974 and 1979.
National League pitchers who won prior to it being the Baseball Pitcher of the Month Award were Joey Jay (July 1958 & May 1961), Lew Burdette (August 1958), Harvey Haddix (May 1959), Roy Face (June 1959), Don Drysdale (July 1959, July 1960 & May 1968), Vern Law (August 1959 & June 1965), Lindy McDaniel (June 1960), Warren Spahn (August 1960 & August 1961), Jim O'Toole (September 1961), Bob Purkey (May 1962), Sandy Koufax (June 1962), Jack Sanford (August 1962), Dick Ellsworth (May 1963), Jim Bunning (June 1964), Bob Gibson (September 1964, June 1968, July 1968 & August 1970), Juan Marichal (May 1966), Gaylord Perry (June 1966), Steve Blass (September 1968), Ken Holtzman (May 1969), Bill Singer (July 1970), Fergie Jenkins (July 1971), Don Sutton (April 1972), Jerry Koosman (April 1973), Tommy John (April 1974), Buzz Capra (June 1974) and Don Gullett (July 1974).
American League pitchers who won prior to it being the Baseball Pitcher of the Month Award were Gaylord Perry (June 1974), Doc Medich (July 1974), Nolan Ryan (August 1974 & September 1976), Jim Hughes (May 1975), Jim Palmer (August 1975), Mark Fidrych (June 1976), Luis Tiant (August 1976) & Frank Tanana (September 1976).