Last week, we looked at the Yankees' pitching depth in their system. Here are three more playoff-bound teams—the Reds, Twins, and Rangers—who all have surpluses at one key position (second base, center field and shortstop, respectively).

The Reds: Second basemen

With All-Star Brandon Phillips signed through 2011 with an option for the following year, Chris Valaika's future in Cincinnati is cloudy at best. A third-round pick in 2006, Valaika is a career .293 hitter in the minors who rebounded from a tough showing at Triple-A last year to hit .304/.330/.408 for Louisville this year, but that line shows off his weaknesses as much as his strengths. He's a good hitter, but lacks power and patience.

The second baseman creating more excitement, even though he's yet to play in a full-season league, is 2009 second-round pick Billy Hamilton. Drafted as a pure athlete with top-of-the-line speed, Hamilton showed surprising bat skills in the Pioneer League this summer to a line of .318/.383/.456 for Billings. He also had 10 triples and 48 stolen bases in just 69 games. Here's the good thing for him and the Reds: Hamilton is three or more years away from the bigs, so he could be a natural follow-up to Phillips.

The sleeper of the group is Henry Rodriguez, a 20-year-old Venezuelan who was one of the talks of the Low-A Dayton team with a season line of .307/.337/.473 that included an impressive 37 doubles and 14 home runs to go with 33 stolen bases. Short and compactly built, Rodriguez has a quick, smooth swing that drives the barrel of the bat through the zone and creates almost shocking power for his size. His swing-at-everything approach needs considerable refinement, but the tools are impressive and had plenty of scouts looking him up this year to find background information.

Twins: center fielders

With Denard Span losing well over 100 points from last year's OPS, 2009's showing is starting to look more like a fluke than a breakout—and a pair of first-round pick are trying to make their run at replacing him down the road. Already in the big leagues to provide speed off the bench in September, 2007 first-rounder Ben Revere gutted through an injury-plagued 2010 to hit .305/.371/.363 for Double-A New Britain, and scouts noted his improved discipline at the plate as well as better base running instincts. A small version of Span, Revere is unlikely to ever hit for power, as his game revolves around getting on base and running, but with a career minor league batting average of .328, he'll get his chances.

Offering far more ceiling—but also far more risk—is 2008 first-round pick Aaron Hicks. His tools are impressive, but he's yet to put it all together. Playing his second season at Low-A Beloit in 2010, Hicks hit .279/.401/.428. His approach is highly advanced for a player so raw, but he also has a tendency to put himself into bad counts, where he gets into a bad habit of chasing pitches. He's an outstanding center fielder with the strongest outfield arm in the system, and while there is plenty of power potential in his frame, it resulted in just eight home runs over 115 games this year. No player in the system matches his ceiling, but scouts are starting to wonder about the likelihood of him reaching it.

Joe Benson is the sleeper. The second-round pick in 2006 was better known for his football prowess at perennial power Joliet Catholic in Illinois, Benson has been slow to develop, but had a breakout year in 2010 while splitting time between High-A and Double-A. A big, muscular athlete with above-average speed, power, and arm strength, Benson's loopy, pull-heavy swing will likely prevent him from ever hitting for much of an average, but even with just a .259 mark this year, he still had an outstanding season with 27 home runs, 19 stolen bases and 47 walks in 123 games.

Rangers: Shortstops

Elvis Andrus has turned into an established big league shortstop. He's also just 22. He has little power, though, and the Rangers have three young guys who could potentially spell him down the road.

The most advanced of the three is just 19-year-old Dominican Leury Garcia, yet he already has a year in the full-season leagues under his belt. Garcia hit just .262/.307/.323 for Low-A Hickory, but he makes consistent contact, and knows how to use his tiny frame to his advantage when working the count. His size bothers many scouts, but at the same time he's a plus-plus runner who stole 47 bases in just 89 games for the Crawdads, and he can be a spectacular, although highly erratic defender who simply needs more maturity in his game.

The shortstop in the system generating the most attention is Jurickson Profar, a 17-year-old native of Curacao who debuted with a .250/.323/.373 line in the college-heavy Northwest League. One of the reasons Profar signed with the Rangers last year ($1.55 million bonus) is that he wanted to play shortstop when many teams preferred him on the mound. Mature beyond his years, Profar has a highly advanced approach and the instincts and actions of a nearly big league-ready defender. For many, he just needs to harness his tools, but like Andrus, he could be a big league product at a very young age.

One of the busiest teams in the international market, the Rangers didn't stop signing shortstops last year when they inked Profar. During the same signing period, they inked Venezuelan Luis Sardinas for $1.2 million. Like Profar, Sardinas is just 17 years old and eons away from the big leagues, but the switch-hitter impressed during his pro debut with a .311/.363/.350 line in the Arizona Rookie League. While lacking Profar's fundamentals and instincts, Sardinas is a potentially flashier defender—but like Garcia and Profar, we're talking about children here, and the rate of attrition for players like these can be astonishing at times.

A version of this story originally appeared on ESPN Insider Insider.