The Prospect Hot Sheet is not a re-ranking of the Top 100 Prospects. This is a snapshot of which top prospects are excelling and which ones are struggling right now. Stats cover the period April 27-May 3.

Contributing: Ben Badler, J.J. Cooper, Matt Eddy and Jim Shonerd.

Team: high Class A Lakeland (Florida State)
Age: 20
Why He's Here: .516/.531/.774 (16-for-31), 1 HR, 3 2B, 1 3B, 6 RBIs, 5 R, 1 BB, 4 SO, 1-for-1 SB
The Scoop: Castellanos went 0-for-4 last Saturday . . . and that's the extent of negative things we can say about the 2010 supplemental pick's recent play. Despite playing in the Florida State League, a veritable pitcher's paradise, Castellanos has opened the season on a 43-for-101 (.426) tear through 25 games. He leads the minors in batting average and ranks fourth in on-base percentage (.477) by virtue of having drawn 12 walks, two of them intentional.

Having demonstrated ample feel for hitting last year in the Midwest League—he batted .312 and led the league with 158 hits—Castellanos is making encouraging strides in the power department this season. First of all, he's a physical 6-foot-4 righty hitter who connected for 36 doubles last season, and scouts often say that home-run power is the final tool to manifest. At any rate, Castellanos collected five extra-base hits last week and now leads the FSL in doubles (nine), slugging (.594) and total bases (60) in addition to average and OBP.
2012 Stats

Team: high Class A St. Lucie (Florida State)
Age: 23
Why He's Here: .367/.424/.900 (11-for-30), 5 HR, 1 2B, 9 RBIs, 6 R, 2 BB, 7 SO
The Scoop: Vaughn homered in three straight games from April 27-29 and went deep in five of the seven games he played last week. He has a Florida State League-leading seven bombs already this season, which is even more impressive when you realize he hit nine in a half-season for St. Lucie last year. Counter-balancing the power binge, however, Vaughn struck out seven times last week, including three times in one game. Swinging and missing will be an acceptable trade-off for home runs at the big league level, but Vaughn still has to graduate from three minor league levels to get there. He's got a chance, but keep in mind that his father Greg, a four-time all-star, already had reached Milwaukee by the time he was 23.
2012 Stats

Team: high Class A Inland Empire (California)
Age: 22
Why He's Here: 0-0, 0.69, 2 GS, 13 IP, 9 H, 2 R, 1 ER, 0 HR, 17 SO, 3 BB
The Scoop: Maronde has made 17 starts as a pro, earning every bit of his shiny 2.43 ERA with a strikeout rate of 9.4 batters per nine innings, a 1.08 WHIP and eight homers allowed. Did we mention that Maronde made every single one of those starts in either the Pioneer or California league, the two most hitter-friendly circuits in the country? Not bad for the former Florida Gator who slipped to the third round of last year's draft because evaluators weren't sure he'd be able to hack it as a starter in pro ball. Maronde has been seriously dealing in his last four starts, logging a 1.67 ERA and 28-to-4 strikeout-to-walk ratio over 27 innings. In that time he's allowed just 23 baserunners in the Cal League, where batters hit about .330 when simply putting bat to ball. By point of comparison, Maronde is charting more rapid progress than recent Angels college-pitcher picks like Garrett Richards and Daniel Tillman.
2012 Stats

Team: high Class A Visalia (California)
Why He's Here:
0-0, 1.29, 1 GS, 7 IP, 4 H, 2 R, 1 ER, 1 BB, 12 SO
The Scoop:
It says something about the Diamondbacks' pitching depth that a prospect as good as Chafin, who shows a plus fastball from the left side and a nasty slider, couldn't crack Arizona's Top 10 prospects list this past offseason. Arizona's supplemental first-round pick last year out of Kent State, Chafin signed for $875,000 at the deadline, and he's living up to that lofty draft status so far this spring. Chafin leads the California League in strikeouts with 45 in 27 2/3 innings while holding hitters to a .190 average. Some scouts see a future reliever when they watch Chafin's delivery, but he's doing everything he can to prove he belongs in a rotation.
2012 Stats

Team: Double-A Frisco (Texas)
Age: 22
Why He's Here: 2-0, 1.50, 2 GS, 11 IP, 7 H, 1 R, 1 BB, 14 SO
The Scoop: Want to know why the Rangers are developing into a seemingly unstoppable juggernaut? Part of the reason is the success stories like Grimm, who largely was a disappointment during his college career at Georgia, where he finished with a career 5.84 ERA and had delivery issues that meant he had poor control and even less command. The Rangers were thrilled to scoop him up in the fifth round of the 2010 draft. In the two years since they've managed to straighten out some of the flaws in his delivery, which has allowed him to throw significantly more strikes while also improving his ability to keep the ball down in the zone. Velocity was never a problem for Grimm, but now that he's paired his 92-95 mph stuff with an idea of where it's going (he's walked six batters in 33 innings), Grimm is a potentially dominating starter.
2012 Stats

Team: high Class A Carolina
Age: 22
Why He's Here: .360/.414/.880 (9-for-25), 8 R, 1 2B, 4 HR, 6 RBIs, 3 BB, 7 SO
The Scoop: The life of a righthanded-hitting first baseman is pretty rough one. You go through your minor league career knowing that you're going to have do everything short of setting yourself on fire at each level to get noticed. As a very sizeable 250+ pounds, Aguilar faces an ever tougher path to the big leagues because a move to the outfield isn't really an option. But if you're going to be a first baseman, the first job is to make sure you hit like a first baseman, and Aguilar has been doing that. After a very strong season in low Class A Lake County last year, Aguilar has been just as good in the early going this season. He's getting on base about 40 percent of the time this season, which pairs nicely with impressive power. If he keeps this up, a midseason move up to Double-A doesn't seem unrealistic.
2012 Stats

Team: high Class A Salem (Carolina)
Age: 22
Why He's Here: .333/.455/.667 (9-for-27), 8 R, 3 2B, 2 HR, 5 RBIs, 3 BB, 5 SO, 5-for-5 SB
The Scoop: Bradley was a tremendously accomplished college player at South Carolina when the Red Sox signed him last year for $1.1 million as a supplemental first-round pick. He has solid tools across the board, all of which play up because of his tremendous baseball instincts. He's gotten off to a terrific start for Salem, where he's batting .360/.470/.539 with more walks (18) than strikeouts (16) and a crisp 10-for-11 stealing bases. Bradley leads the Carolina League in OBP and ranks seventh in the minors in that category, while his defense continues to get strong grades as well.
2012 Stats

Team: high Class A Stockton (California)
Age: 21
Why He's Here: .385/.407/.769 (10-for-26), 6 R, 3 2B, 2 HR, 5 RBIs, 1 BB, 5 SO, 1-for-1 SB
The Scoop: When the A's traded closer Andrew Bailey and outfielder Ryan Sweeney to the Red Sox in December, the main player they were getting in return was outfielder Josh Reddick, with righthander Raul Alcantara an intriguing sleeper arm included in the package headed to Oakland as well. Regarded as the third player Oakland received, Head has shown promising early signs for the A's. After playing first base last year for the Red Sox, Head is splitting his time between third and first this year, but it's the offense that will have to carry Head. So far so good, as his 1.100 OPS ranks first in the Cal League and 11th in the minors, though he'll have to learn to tighten his strike zone against more advanced pitchers.
2012 Stats

Team: low Class A West Virginia (South Atlantic)
Age: 19
Why He's Here: .400/.438/.567 (12-for-30), 8 R, 3 2B, 1 3B, 3 RBIs, 2 BB, 4 SO, 2-for-4 SB
The Scoop: Hanson looks like the early breakout story of the 2012 season. He ranked as one of the top prospects in the Rookie-level Gulf Coast League a year ago, even as he played through a finger injury that hampered his numbers. With a .402/.435/.675 slash line in 124 plate appearances, Hanson ranks third in the minors in hitting and 10th in OPS. He's reached base at least once in 25 of 27 games, and while he figures to cool off a bit, his bat is for real and he's quickly become one of the Pirates' most exciting prospects.
2012 Stats

Team: high Class A Visalia (California)
Age: 20
Why He's Here: 2-0, 1.98, 2 GS, 13 2/3 IP, 11 H, 3 R, 3 BB, 14 SO
The Scoop: Holmberg found the California League can be an inhospitable place last year, when he went 4-6, 4.67 in 13 starts for Visalia in the second half. With an effective sinking fastball and plus command, Holmberg has the tools to survive the Cal League, and his past struggles have been a distant memory so far in 2012. Holmberg had one rough outing on April 17 against Bakersfield, giving up eight hits and six runs in 4 2/3 innings, but he's shined in his other five starts, allowing two runs or fewer in each of them. He held San Jose to one run over seven innings while striking out eight last Friday then added six more strikeouts over 6 2/3 innings on Thurdsay.
2012 Stats

Team: Double-A Harrisburg (Eastern)
Age: 24
Why He's Here: 0-0, 0.00, 1 GS, 7 IP, 6 H, 0 R, 0 BB, 5 SO
The Scoop: Rosenbaum has never been a particularly sexy prospect. Thanks in part to his average 89-91 mph fastball, Rosenbaum lasted until the 22nd round of the 2009 draft after a solid career Xavier. Since then, he's compiled a career minor league record of 21-14, 2.20. But even with that, the Nationals have moved the 24-year-old on the slow track—he returned to high Class A Potomac to start 2011 after a strong finish there in 2010. Now he's returned to Double-A Harrisburg after finishing strong there in 2011. Last year Rosenbaum had to wait for 19 starts to get the call to Double-A, he's trying to speed his ascent to Triple-A by handcuffing hitter after hitter with his cutter. He's currently working on a 23-inning scoreless streak and, as always, he isn't giving up home runs—the one he's allowed this year means he's now given up 13 in 388 career pro innings.
2012 Stats

Team: high Class A Bakersfield (California)
Age: 22
Why He's Here: 1-0, 0.00, 1 GS, 5 IP, 3 H, 0 R, 0 BB, 9 SO
The Scoop: This shouldn't be possible. We're more than a month into the season and the pitcher who leads the minors in ERA is a pitcher from the California League. You know the California League? It's the one where one bad outing can make an ERA look like the moniker for Boeing's latest jet. Not only has the former Rice lefthander avoided a bad outing, he's yet to have a bad inning. Cingrani did allow a pair of runs, one of which was earned, in his second start of the season. Since then he's thrown 18 scoreless innings, allowing eight hits and three walks while striking out 26. Cingrani had an 8.59 ERA when Rice tried starting him in college, but his 0.32 ERA this year makes it clear that starting now suits him.
2012 Stats

Team: Double-A Chattanooga (Southern)
Age: 23
Why He's Here: .429/.529/1.000 (6-for-14), 2 HR, 2 2B, 4 RBIs, 5 R, 3 BB, 4 SO, 3-for-3 SB
The Scoop: Lemmerman's one of those players who may not have explosive tools, but he gets the most of what he has. A fifth-round pick from Duke in 2010, Lemmerman made it to Double-A last year in his first full season but wore down and put up a .234/.318/.390 line in 77 at-bats in Chattanooga. But he's a better hitter than those numbers show. Rejoining the Lookouts this year, Lemmerman got off to a slow start in the first two weeks but has hits in seven of his last eight games, including four multi-hit efforts. He's not known for power, but he homered in back-to-back games against Huntsville this week, punctuated by a 3-for-4 performance Thursday that included a homer and a double.
2012 Stats


When developing a pitcher, the Pirates like to say they are painting a picture. The focus is on long-term success, so short-term statistical struggles might mask some significant improvement in the team's eyes. But while the Pirates were focused on the process, everyone else was noticing that RHP Gerrit Cole, the No. 1 pick in last year's draft, was not exactly mowing down Florida State League lineups. Perceptions may begin to change following the 21-year-old's outing on Monday. In it, Cole struck out six, while allowing one hit and one walk in six scoreless innings at Jupiter for his best outing as a pro . . . Blue Jays C Travis d'Arnaud was hitting under .200 after the first two weeks of the season, but the 23-year-old is riding a 13-game hit streak to boost his overall line to .283/.351/.424 in 111 plate appearances for Triple-A Las Vegas . . . With six more shutout innings this week for high Class A Bradenton, 20-year-old Pirates RHP Jameson Taillon lowered his ERA to 1.49 in 24 2/3 innings and has a 28-4 K-BB mark . . . The way Double-A Binghamton RHP Zack Wheeler has been pitching, the only thing that could slow his progress would be an injury. Unfortunately for the Mets top prospect that's exactly what happened when the 21-year-old suffered a torn nail on his right middle finger that led to his being scratched from today's start. (He also dealt with a cracked nail issue in the Giants system in 2010.) Wheeler struck out six over 5 2/3 innings this week, allowing two hits and one run, and over his last four starts he's notched a 1.19 ERA and 26-to-11 strikeout-to-walk ratio over 22 2/3 innings. With luck, his disabled list stay will be a short one . . . Dodgers RHP Garrett Gould was roughed up in his April 23 outing with high Class A Rancho Cucamonga, giving up six earned runs in three innings. Perhaps not coincidentally, that start was in Lancaster, one of the minors' ultimate hitter's havens. Gould, 20, bounced back with six quality innings in his only start of this week, allowing one run on four hits with a career-high 12 strikeouts against Lake Elsinore. The 12 whiffs moved Gould up to third in the Cal League . . . Rangers RHP Cody Buckel had what qualified as a tough start by his standards last Friday for high Class A Myrtle Beach, giving up three runs on nine hits in six innings, but he came back with another gem on Thursday. Buckel, 19, reeled off seven scoreless innings, his longest outing of the year, and struck out eight, allowing three hits and three walks. He dropped his ERA to 1.31 in 34 1/3 innings for the year . . . 3B Ryan Wheeler could be pushing for a big league look with the Diamondbacks after getting off to a hot start with Triple-A Reno. The 23-year-old hit .464/.484/.750 (13-for-28) with a homer, a double and two triples this week. He's riding a nine-game hitting streak that included a stretch of four straight multi-hit games earlier this week


Daisuke Matsuzaka, rhp, Red Sox. It seems at times that Matsuzaka is almost a forgotten man in Boston, but by the end of this month he'll be forcing Red Sox general manager Ben Cherrington to make some tough decisions. The 31-year-old had the best outing of his rehabilitation (following Tommy John surgery) as he allowed one run, three hits and two walks while striking out seven in 4 2/3 innings with Double-A Portland. According to the Portland Press Herald, Matsuzaka's fastball was clocked at 93 mph. With Boston's (possibly temporary) addition of Aaron Cook to the rotation this weekend, the Red Sox already have six starters. When Matsuzaka proves he's ready, the club will have to figure out a way to fit seven starters into five spots.


Aaron Miller, lhp, Dodgers: When the Dodgers' drafted Miller in the supplemental first round in 2009, they thought they were getting a fresh-armed starter who could consistently sit at 91-95 mph. The hope was that Miller, a two-way player in college, would see his stuff improve now that he could focus on pitching full-time. Instead, his stuff has backed up and he's thrown a lot more games sitting 88-90 mph than 92-94. To his credit, he's shown he can battle hitters, but in Double-A that is proving harder to do. This past week he had his worst outing of the season, giving up seven runs and 10 hits in 5 2/3 innings.

Ronny Rodriguez, ss, Indians: Rodriguez runs well, has a strong arm and flashes surprising raw power, but the light bulb has yet to turn on. Rodriguez, 20, remains crude, which he showed this past week going 1-for-21 (.048) to drop his season line with high Class A Carolina to .188/.225/.282 in 89 plate appearances. Rodriguez has the defensive tools to be a quality fielder, but even there he shows his crudeness and has already made eight errors.

Ronald Torreyes, 2b, Cubs: Torreyes has shown some good things and some bad early in the high Class A Florida State League season. The pint-sized second baseman is hitting just .205/.274/.289 in 23 games, including a 1-for-25 (.040) stretch over the past week. The good news is that Torreyes' terrific hand-eye coordination and bat control have not deserted him. Even this past week, he has not struck out once, and he only has seven strikeouts all season. His early performance has been underwhelming, but as a 19-year-old in the FSL, there's no need to panic here.

Gerardo Concepcion, lhp, Cubs: The Cubs gave Concepcion a rather stunning five-year major league deal worth $6 million in March, a move that was widely derided throughout the international scouting community. While the deal was seen as a significant overpay, Concepcion at least figured to be able to handle the low minors without much issue due to his success in Cuba's Serie Nacional at a young age. Instead, the 20-year-old's first two low Class A Peoria starts have resulted in 12 rus in 5 2/3 innings, including a start this week in which he couldn't even get out of the first. Concepcion is throwing strikes, but he's also struck out just two of the 32 batters he's faced, a pattern consistent with his middling strikeout rate in Cuba with a very hittable fastball that sits in the high 80s.


Nate Freiman, 1b, Padres. From the organization that brought you Kyle Blanks comes another monstrous, righty-hitting first baseman who's more agile than he looks. Still, when you're built like Nate Freiman—that would be 6-foot-7 and 225 pounds—the only positions generally open to you are first base or pitcher. An eighth-round senior sign from Duke in 2009, Freiman has moved deliberately through the Padres system, spending full seasons at each Class A level and swatting a total of 36 homers in that time. While his slow pace means he's already 25 as he plays for Double-A San Antonio this season, Freiman is doing his best to turn himself into a prospect, one who's batting .301/.351/.650 through 103 at-bats on the season. After going deep three times last week he leads the Texas League with 10 home runs.


Steven Moya, rf, Tigers. Born in Puerto Rico, Moya lived in the Dominican Republic prior to signing with the Tigers in 2008 as an international free agent. At 6-foot-7, Moya looks like he should be playing down on the block for a college basketball team, and his long arms gave him trouble getting to his plus raw power in game situations early in his career. After barely hitting above .200 last year in low Class A West Michigan, Moya is showing signs of life in his return to the league as a 20-year-old, hitting .377/.421/.507 in 19 games. The most impressive sign may be that he's struck out just 10 times this season, a significant improvement over his 127 whiffs in 86 games a year ago.