Key players for playoff contenders

Updated: September 25, 2012, 10:05 AM ET
By Buster Olney

Scouts are scattered all over ballparks these days, preparing for the postseason, looking for weaknesses, forming opinions on which hitters to avoid and which hitters to go after.

Each of the playoff teams will have particular players who will be barometers for their club's performance -- linchpin guys.

Here are those players, among the teams that would qualify for the postseason as of this morning.

Texas Rangers, Yu Darvish: A month ago, their rotation looked to be a real concern in the postseason, but Darvish has turned it around in recent weeks; he's got 42 strikeouts in his last 37 innings, with a 1.46 ERA. Texas will need more of the same next month.