There is still plenty of baseball left to play. With the exception of the Atlanta Braves in the National League East, every division is more or less up for grabs.
But the fate of teams’ pursuit of the playoffs and World Series can sometimes depend on the performance of key players. For instance, if A.J. Burnett, who has sported a 2.73 ERA (versus park-adjusted 130 ERA+) to date, were to pitch poorly in the playoffs, his regular-season triumphs would all be for null.
Below are five players who must prove they're clutch in the 2013 pennant races.