[3] Keane was temporarily spared, but Busch was secretly negotiating with Leo Durocher (then a coach for the Los Angeles Dodgers) to become manager at the close of the 1964 season.

However, in the last two weeks of the season, the front-running Philadelphia Phillies — who had seemed a lock for the pennant — unexpectedly began to unravel while both the Cardinals and Cincinnati Reds got hot.

The Phillies lost ten straight games, creating a four-team scramble for the National League pennant, involving the Phils, Cards, Reds and San Francisco Giants.

[6] On the final day of the regular season on Sunday, October 4, the Phillies blanked the Reds 10–0 and the Cardinals took the Mets 11–5 to avoid a three-way playoff and clinched their first NL pennant since 1946;[7] they then defeated the New York Yankees in a seven-game World Series.

Instead, Keane handed owner Busch and new general manager Bob Howsam (Bing Devine had been fired as GM on August 17) a surprise letter of resignation that he had written late in September, at the height of the pennant chase.

The Cardinals then bypassed Durocher entirely and instead hired longtime fan favorite Red Schoendienst, a Hall of Fame second baseman and one of Keane's coaches, as the club's new manager.

Keane is described in Jim Bouton's Ball Four as being prone to panic, and someone who was "willing to sacrifice a season to win a game" by putting injured stars into the lineup before their injuries had fully healed.