Fister pitched in the second game of the ALDS against the Oakland A's, picking up a no decision in a 5–4 victory while giving up two runs in seven innings. He also got a no-decision in Game 1 of the 2012 ALCS against the New York Yankees, despite surrendering no runs in innings of work. Fister was struck in the head by a line drive off the bat of Giants outfielder Gregor Blanco during the second inning of Game 2 of the 2012 World Series. Fister continued to pitch the game, holding the Giants to one run over six innings before turning it over to the bullpen.