Here is a look at young talent on each of the 2010 playoff teams, beginning with the American League and the Minnesota Twins. The focus here is on players who were rookies, or any player 24 years old or younger.
Alex Burnett, RHP: 23-year-old rookie spent most of the year in the Twins pen as a mop-up guy, posting a 5.29 ERA with a 37:23 K:BB in 48 innings, with 52 hits allowed. A 12th round pick in 2005 out of high school in California, he has decent-but-not-spectacular stuff and is most likely to end up as a utility bullpen pitcher or occasional spot starter down the road.
Jeff Manship, RHP: 25 year old rookie, a 14th round pick out of Notre Dame in 2006. 5.28 ERA this year with a 21/6 K/BB in 29 innings, 34 hits allowed. Like many Twins pitching products, he has average velocity (88-92 MPH) but a feel for pitching and good control. He's been a starter in the minors, but in the majors he projects as more of a long relief type, like Burnett.
Trevor Plouffe, INF: 24 years old, rookie, drafted in the first round in 2004 from high school in California. He hit just .146/.143/.317 in 22 games for the Twins this year, following a .244/.300/.430 campaign in Triple-A. He hit 17 homers this year between the two levels. He's a capable defender up the middle, but is limited offensively by poor on-base skills. He could end up having a long career as a bench guy, but I don't see him as a consistent regular.
Ben Revere, OF: 22 year old rookie, first round pick from a Kentucky high school in 2007, hit .305/.371/.363 with 36 steals in Double-A, .179/.233/.179 in 13 games in the majors. He needs more minor league time and I don't expect to see him as a consistent regular in the majors before 2012. Lack of power is a significant issue, but he makes contact and can fly.
Danny Valencia, 3B: 26 year old rookie having a surprisingly good season, hitting .311/.351/.448 for the Twins with better-than-expected defense at third base. A 19th round pick in 2006 from the University of Miami, Valencia is probably more of a .280 hitter with moderate power in the big picture, but he's done more than enough this year to keep him in Minnesota's plans long-term.
Delmon Young, OF: It seems like he's been around forever, but Delmon played most of '10 at age 24 and didn't turn 25 until last month, so he qualifies as a "young player" under the definition used in this article. Hit .298/.333/.493 this year with 21 homers, 46 doubles, and 112 RBI. He still has plate discipline issues and likely always will, but his Isolated Power spiked this year. If he has anything like a normal age curve, he could have some really excellent seasons when he hits the age 27-29 window in a few years. His defense is bad and drags down his WAR value to 2.1, but that was still a career high by far.