The availability of Madison Bumgarner
Games 1 and 5 starter Madison Bumgarner was reportedly available if needed to record a critical out in Game 6. He wasn't needed, which means his availability could expand to an inning or two in Game 7. Bumgarner has far and away been the most dominant starting pitcher during the postseason, posting a 1.13 in 47 2/3 innings. He's 2-0 against Kansas City in the World Series with a 0.56 ERA. Perhaps more important than that, he has experience throwing in relief during the postseason. He pitched two scoreless in Game 6 of the 2010 NLCS. He's a lethal Game 7 weapon.

http://sports.yahoo.com/blogs/mlb-big-league-stew/three-keys-for-the-giants-and-royals-in-world-series-game-7-050627029.html