Minor Impacts: September 3

Every Thursday throughout the season, Minor Impacts takes a look at some of the hottest minor league players that could have impacts at the Major League Level in the near future. Some of the players we’ve educated you on before their promotions include: Vince Mazzaro, Andrew McCutchen, Gordon Beckham, Alex Avila, Brian Matusz, Marc Rzepczynski, Jake Fox, Nolan Reimold, Daniel Bard, Bud Norris, and Mat Latos.

With the MLB rosters expanding from the standard 25 men to as many as 40 players, we’re switching things up this week and taking a look at some of the more interesting prospects making their MLB debuts.

Buster Posey: There was some talk that San Francisco would delay Posey’s promotion to the Majors in an effort to save some money, but the organization did the right thing and brought him up for a taste of the Majors. Posey has proven that his bat and glove are MLB ready. In a perfect world (keeping in mind their GM loves veterans), Posey would spend 2010 seeing 60-70% of the playing time behind the dish with San Francisco. A veteran catcher – Bengie Molina if he’s up to the decreased role – would then see the remainder of the playing time while serving as a mentor to the rookie backstop. There isn’t much that Posey cannot do with the bat; he hits for power (.200 ISO), for average (.310 at AAA) and takes his fair share of walks (11.9% in AAA). Overall, the 22-year-old prospect hit .325/.416/.531 in 422 at-bats at high-A and triple-A.

Tyler Flowers: Flowers cannot match Posey’s overall game but this White Sox prospect could make veteran A.J. Pierzynski expendable after the 2010 season – if not before. Flowers might struggle to hit for a high average because he has trouble making contact sometimes (30.5 K%), but he posted a .246 ISO in 248 double-A at-bats before moving up to triple-A. Flowers, an average backstop, also takes a ton of walks, having posted a 19.2% walk rate in 2008 and a rate of 18.7% in double-A in ’09. Flowers has been a lefty killer in his minor-league career and hit .358 against them this year with an OPS of 1.119.

Wade Davis: With the trade of Scott Kazmir, the Rays acquired a few interesting young names, while also opening up a rotation spot for either Andy Sonnanstine or Davis. The right-handed rookie has been a top prospect in the system for a few years now but his numbers were just good in triple-A… as opposed to great. Now 24, Davis allowed 139 hits in 158.2 innings of work at triple-A in 2009, while posting a walk rate of 3.43 BB/9 and a strikeout rate of 7.86 K/9. He is the early favorite to replace Kazmir in the 2010 starting rotation, although Sonnanstine has the experience edge.

Michael Brantley: Obtained as part of the C.C. Sabathia deal last year, this outfielder is not a slam-dunk star but he has more than enough talent to be a valuable contributor to the Indians and your fantasy squad. Brantley understands his game very well for a 22 year old. The left-handed hitter had a bit of a down year in triple-A this season but he still walked more than he struck out (1.23 BB/K) and he posted an 11.4 BB%. He stole a career high 43 bases in 48 attempts but hit just .267 (.288 BABIP). At worst, he should be a very valuable fourth outfielder and pinch runner.

Josh Thole: Another catcher, Thole was converted from first base to catcher and has really improved his value to the point where he is one of the brighter up-and-coming backstop prospects. A left-handed hitter, Thole has hit .300+ in each of the past two seasons, including .328/.395/.422 in 384 at-bats in double-A this year. He’ll need to keep that average up because he has almost no power to speak of, as witnessed by his .094 ISO.

Neil Walker: Walker’s star has diminished significantly from the days when he was the top prospect in the Pirates system. He’s struggled in triple-A for two straight seasons and is currently sandwiched in between Andy LaRoche and Pedro Alvarez. Walker could end up as a AAAA slugger, or a bench player, which is a far cry from the days that the Pittsburgh native was the club’s No. 1 draft pick out of high school. This year he hit just .266/.312/.484 with 14 homers in 353 at-bats. The .218 ISO is nice, but the 6.6% walk rate is not.