Minor League Barometer: Prospects Proving their Worth

Two huge promotions in the prospect world this week, as Anthony Rizzo made his much-awaited debut at first base for the Cubs, while strikeout machine Trevor Bauer gets the starting nod Thursday for the D-Backs.

Meanwhile, the Oakland Athletics were powered to victory Sunday by two rookies, as A.J. Griffin went pitch-for-pitch with Matt Cain in his MLB debut, and catcher Derek Norris hit a walk-off three-run bomb for his first big-league home run. Tampa Bay rookie Chris Archer dueled with Stephen Strasburg and certainly held his own, allowing two earned runs over six innings while fanning seven.

With Bryce Harper and Mike Trout both exceeding everyone's wildest expectations in their first campaigns, it certainly pays to follow the phenoms. Let's look at who's on deck in this week's Minor League Barometer.

UPGRADES
 
Jean Segura, SS, LAA - Segura finally appears fully recovered from last season's hamstring woes, as he is slashing .287/.330/.413 with seven home runs, 34 RBI and 27 steals through 75 games for Double-A Arkansas. Though power may not end up being his forte, the 22-year-old has still shown some pop with his standout speed. He could draw a few more walks, but he doesn't strikeout an exorbitant amount. Segura is a possible .300 hitter with 30-steal potential at a scarce position at the big-league level.

Mason Williams, OF, NYY - The 20-year-old outfielder has been scalding the ball recently for Low-A Charleston, batting .372/.386/.767 over his last 10 games. Perhaps most notable, Williams has hit four home runs and knocked in seven runs over that span. In 63 games overall, Williams is batting .307/.356/.508 with eight home runs, 27 RBI and 18 stolen bases. He's also fanned just 28 times this year, showing a knack for putting the ball in play. If his power surge continues, Williams could be one of the more coveted prospects in the game heading into 2013.

Kyle Crick, P, SF - The 19-year-old righty has not allowed an earned run over his past three starts for Low-A Augusta, a span of 18 innings. Over that time, Crick has surrendered just five hits, walked eight and punched out 22 batters. In all, Crick has notched a 2.79 ERA and 73:34 K:BB ratio in 58 innings. Though his control needs work, it is hard to argue with the overall results thus far, which include a minuscule .190 BAA, and a respectable 1.30 GO:AO ratio. The 6-foot-4, 220-pounder could be a future star for the Giants.

Jackie Bradley, OF, BOS - Bradley recently earned a promotion to Double-A after incredible numbers at High-A Salem. The 22-year-old batted .359/.480/.526 with three home runs, 34 RBI and 16 steals in 67 games. Considering defense was supposed to be Bradley's greatest strength, his superior batting line only adds to his intrigue as an up-and-coming phenom. He doesn't project to hit for much power but has excellent plate discipline and decent speed. Bradley's eagle eye could have him on the fast track to the majors, in particular due to the struggles of the Red Sox to find durable outfielders lately. Certainly Bryce Brentz will have something to say about that, though.
 
CHECK STATUS

Brett Jackson, OF CHC - Now that Anthony Rizzo has finally gotten the call to the big leagues, Jackson is the next Cubs prospect to watch. Jackson smashed home runs in three straight games over the weekend, pushing his power numbers to 11 dingers and 31 RBI. However, he's fanned an absurd 110 times in 74 games and is hitting just .238 against right-handed pitching. He's clearly a bit lost at the dish despite possessing a nice combination of power and speed. With the glut of outfielders on the Cubs with Bryan LaHair's move from first base, Jackson will likely stay down in Triple-A for the time being.

Trevor Rosenthal, P, STL - The 22-year-old from Cowley County Community College has been a pleasant surprise for the Cardinals. Rosenthal has a 2.85 ERA and 71:34 K:BB ratio through 82 innings for Double-A Springfield. Opposing batters are hitting just .203 against the 6-2 righty. Though he induced more ground balls in the past, Rosenthal has still accumulated a 1.20 GO:AO ratio in 2012. Since this is his first full season of enormous success, make sure Rosenthal is the real deal before snatching him. Bear in mind that he did fan 133 batters in 120 innings last year at Low-A Quad Cities, though.

Sean Gilmartin, P, ATL - The No. 28 overall selection in the 2011 draft, Gilmartin has been dealing over his past 10 starts. He has compiled a 3.39 ERA and 53:17 K:BB ratio in 61 innings. The 22-year-old lefty has held left-handed hitters to a putrid .170 BAA. Gilmartin also benefits from the recent struggles of Randall Delgado and Julio Teheran, as well as the injury to Arodys Vizcaino. Nevertheless, Gilmartin's upside is limited despite his supreme command. It's tough to see him as a front-of-the-rotation starter since righties hit him fairly well, and he isn't overpowering. That's not to say he can't be a successful pitcher at the highest level, only that he may not live up to his lofty draft slot.

Gerrit Cole, P, PIT - Cole has not been pushed as hard as fellow collegiate draft picks Trevor Bauer and Danny Hultzen despite being the No. 1 pick out of UCLA last season. Cole dominated High-A as he should have, with a 2.55 ERA and 69:21 K:BB ratio in 67 innings. However, in just his second start for Double-A Altoona, the 23-year-old was bombed for three runs on five hits in just one inning pitched. Despite stellar pitching in 2012 at the big-league level, none of the Pirates' current starters are homegrown products. With the lack of pitching developed on the Pittsburgh farm over the last decade, Cole may not be as sure of a thing as people think.
 
DOWNGRADE
 
Jenrry Mejia, P, NYM - The 22-year-old is back in the bullpen, which clearly diminishes much of his fantasy value. In his limited duty recently he hasn't been sharp either, allowing eight runs over his last 1.2 innings. Mejia has failed to a record a strikeout over that span despite walking four batters. Frank Francisco is on the DL for the Metropolitans with Bobby Parnell serving as the interim closer. The Mets have had one of the worst bullpen ERAs in the bigs this season. In other words, despite a clear call for Mejia's talents, he hasn't been able to put things together thus far in 2012.

Tim Beckham, SS, TB - The Barometer has never been kind to Beckham. He was viewed as a reach as the No. 1 overall selection in 2008. He has never hit above .275 in any single season since entering the minors, with a career-high .346 on-base percentage. He has only stolen more than 20 bases once and hit double-digit home runs once as well. Add a 50-game suspension for drug issues earlier this season and a .197 batting average in 16 games since his return to Triple-A Durham, and Beckham continues to be a colossal disappointment for the Rays.

Keyvius Sampson, P, SD - Sampson had a breakout 2011 campaign in which he posted a 2.90 ERA and 143:49 K:BB ratio in 118 innings at High-A. The 21-year-old has come crashing back down to earth this season, with a bloated 5.90 ERA. Command has been Sampson's biggest problem, as he has walked 44 batters in 71.2 innings, including 31 over his last 47.2 innings. He has walked at least three batters in eight of his last nine outings. The strikeout potential is there, but Sampson will not be able to advance until he can improve his control.

Michael Choice, OF, OAK - Oakland's track record of developing hitting prospects has not been the greatest in recent memory. The aforementioned Derek Norris and Josh Reddick were already essentially MLB-ready by the time they were traded to Oakland. Meanwhile, Chris Carter, Grant Green and Michael Taylor are just a few names of former hot-shot prospects whose stocks have taken a nosedive during their time with the A's organization. Choice could be headed down that path as well, as he is batting just .171 over his last 10 contests. Perhaps of greater concern, though, has been the power outage for Choice this season. After belting 30 home runs for High-A Stockton in 2011, the 22-year-old has just six long balls in 73 games for Double-A Midland. As power is his greatest asset, Choice certainly has some kinks to work out to place himself back on the prospect map.