Note: this is not a re-ranking of current prospects. A new top-50 prospects list will be released this off-season.
Stats through Thursday, July 4
40. James Simmons
The A's top pick in 2007 looked to be back on the road to the big leagues last season when he posted a 2.98 in 63.1 relief innings between Double-A Midland and Triple-A Sacramento. It was Simmons first full season back after he underwent shoulder surgery in 2010. Simmons wasn't invited to big league spring training this year, but he was part of the A's minor league spring mini-camp and he was called upon frequently by the big league team early in spring training. Simmons began the year in Sacramento as a reliever. He struggled out of the gate, however, and was sent down to High-A Stockton after posting a 7.16 ERA and walking an uncharacteristic eight batters in 16.1 innings.
Since joining the Ports, Simmons has moved back into the starting rotation, where he was for the majority of his career before the surgery. He has pitched well for the Ports, posting a 3.51 ERA in 51.1 innings. He has a 38:9 K:BB ratio and he has allowed just four homeruns. It's difficult to know where Simmons fits in with the A's for the rest of this season. He is eligible for minor league free agency at the end of the season and could find a better opportunity in a different organization.
Status: Back in High-A
39. Andrew Werner
Acquired in the Tyson Ross deal from the San Diego Padres this past off-season, Werner came into spring training with an outside chance of winning a spot in the A's rotation. The left-hander was a terrific story with the Padres. Signed out of the independent leagues, he reached the big leagues in less than two years. A "feel lefty," Werner doesn't have much margin for error, but he has excellent command, the ability to mix his pitches and is a strong competitor.
It took a little while for Werner to find himself with his new organization. He struggled during spring training and through the first month of the year with Sacramento. He found a mechanical flaw towards the end of April and, since correcting it, has been a solid starter for the River Cats. Although his ERA stands at 5.50 through Thursday, Werner has been better than that number would indicate this season. He has walked only 2.15 per nine innings and carries a decent 6.36 K/9 rate. Werner's homer rate is up over previous seasons (0.95 HR/9), but seven of the 11 homers he has allowed this season have come on the road. PCL parks outside of the River Cats' home park tend to favor hitters. Sonny Gray and possible Bruce Billings are ahead of Werner on the A's starting pitching depth chart, but he is still very much in the picture should the team suffer a rash of injuries. The A's could also give Werner a look out of the bullpen in September if they need more left-handed pitching.
Status: Holding steady
38. Seth Streich
It took awhile for Streich to find his footing this season with the Low-A Beloit Snappers. The A's 2012 sixth-round pick had an ERA above six heading in June. That ERA was mostly the result of two very poor outings, but he still wasn't as consistent early in the season as a pitcher of his talents is expected to be. That all changed around the start of June and his overall stat line has improved along with it. In June, Streich had an ERA of 1.54 and he earned a Pitcher of the Week honors. He finished the month with three straight starts of six innings or more with two or fewer runs allowed.
Streich has a solid sinking fastball and a decent breaking ball, but he is still working on his change-up. The sinking fastball has allowed him to keep the ball in the park, as he has given up just two homeruns in 79.2 innings this season. Streich's command has improved as the season has worn on, and he has walked just five batters over his last 24.1 innings. If Streich can master the change-up, he could be a breakout candidate next season with his ability to induce groundballs and his 91-94 MPH velocity.
Status: On the right path
37. Tyler Vail
After the last three seasons, Vail may petition the league to start the season in June rather than in April. In 2011, the right-hander struggled through the first three months of the season with Low-A Burlington before being sent to short-season Vermont. Last year, Vail injured his shoulder in spring training and spent the first three months rehabbing at extended spring before going to Vermont for the rest of the year. This season, Vail struggled out of the gate with the Low-A Beloit Snappers before landing on the DL in mid-May. He has found his footing recently, however, as he has settled into a role as a late-inning reliever for the Snappers.
The A's 2010 fourth-round pick was a starter throughout his career before moving to the bullpen this season. His ERA was above eight in April and he managed only 14.1 innings pitched between April and May. Healthy again in June, Vail turned in a solid month. In 12.1 innings, he posted a 1.46 ERA and saved two games. Vail struck out three in one inning in his only July appearance thus far. Vail has a promising fastball and breaking ball, but command has always been an issue. His command has been better of late and he has done a good job keeping the ball on the ground. A solid finish to this season will put him in position to join the Ports next year.
Status: Healthy and throwing strikes
36. T.J. Walz
Walz had a solid season for the Ports in 2012, his first full professional campaign. In 99.2 innings, Walz posted a 3.16 ERA and struck-out 112 while walking 36. Despite that solid season, Walz was forced to repeat the California League, as the A's had a surplus of pitching at the Double-A and Triple-A levels. Things haven't gone as well for Walz with Stockton thus far this season. In 39.1 innings, he has a 6.41 ERA and a 38:22 K:BB ratio.
Walz has had good command during his professional career, so his struggles finding the strike-zone this year have been surprising. He has still struck-out nearly a batter an inning and he has a good groundball rate, but his HR/9 and H/9 rates have gone up. Walz has good stuff. Assuming he isn't hurt, he could put together a strong second half and rescue his season.
Status: Struggling with command
35. Aaron Shipman
Injuries have slowed the development of the talented Shipman, who was the A's third-round pick in 2010 out of a Georgia high school. It has been more of the same for Shipman this season, as he missed two months on the disabled list. The outfielder returned to the active roster for Beloit on Sunday after a brief rehab stint in the Arizona Rookie League.
Before landing on the DL, Shipman struggled in 17 games with the Snappers. He hit only .140, although he did sport a solid 14:16 BB:K. Shipman spent part of his rehab time working on his swing mechanics and reportedly saw significant progress with his swing during his six games in the Rookie League. He is 4-for-his-first-10 with four walks in his three games since returning to Beloit. Shipman profiles as a classic leadoff hitter. He has an excellent eye and well above-average speed. He can be too passive at the plate at times, something he and the A's coaching staff have worked on extensively. If he can find a way to blend his strike-zone judgment with a more aggressive approach to swinging at strikes, he could blossom as a hitter. Although he has been a pro since 2010, Shipman is still young at 21-years-old.
Status: Just back from the DL
34. B.J. Boyd
The A's fourth-round pick out of Palo Alto High School last season, Boyd made a strong first impression by posting a .401 OBP and stealing 16 bags in 39 games with the Rookie League A's last year. The A's chose to have Boyd spend the first half of this season at extended spring training, giving the former two-sport star an opportunity to receive extra coaching and baseball conditioning. He has gotten off to a fast start with the short-season Vermont Lake Monsters and could be poised to make his full-season league debut by the end of this year.
Boyd turns 20 later this month, but he is playing like a much older player thus far for the Lake Monsters. Despite the team's overall offensive struggles, Boyd has been blistering the ball, posting a .397/.441/.603 line in 63 at-bats. His running game has yet to get going (one stolen base in four chances), but everything else about his game has been clicking. Boyd has even shown more power than he did last year, already homering twice and picking up a triple and five doubles. The A's don't want to rush Boyd, as he was somewhat raw coming out of high school because of the time he spent on football. But if he continues to hit at the pace he has with Vermont initially, he will see time on the Beloit Snappers' roster by the end of the year.
Status: Red hot
33. B.A. Vollmuth
It has been a very strange year for Vollmuth, the A's third-round pick in 2011. The Southern Miss alum spent the second half of the 2012 season in High-A, so he was expected to excel with the Ports this season. Instead, he got off to a very slow start and he was in danger of a demotion back to Low-A. He has picked up the pace considerably over the past five weeks, however, and looks poised to at least salvage what looked six weeks ago to be a lost season. For the season, Vollmuth is hitting .214/.288/.429 with 13 homers and a 92:26 K:BB ratio. He hit only .155 in April, but did hit for some power, collecting six homeruns. In May, he cratered, batting only .090 with no homers in 19 games. June was better, however, as he hit .335/.371/.602. So far in July, Vollmuth has two homers in 17 games.
Vollmuth has a solid swing and power to all fields, but he has struggled with pitch recognition all season. Even as his bat has heated up, Vollmuth still has struggled to keep his K:BB ratio at a reasonable rate. He walked only six times in 26 games in June and has an 8:1 K:BB thus far in July. For Vollmuth to reach his potential as a hitter, he will need to be able to stay out of so many two-strike counts. Hitters tend to be more aggressive in the hitter-friendly California League, but the A's still like to see the K:BB ratio better than the more than 3:1 that he is currently carrying. With one more homerun, Vollmuth will tie his total from last year and he has a strong chance to reach 20 by the end of this season. His plate discipline will likely need to show improvement to put him on-track for a promotion to Midland next year, however.
Status: Recovering from slow start
32. Shane Peterson
Peterson was the talk of the A's organization early in the year. After several seasons stuck at the Double-A level, Peterson finally established himself at the Triple-A level last year with a breakout campaign for Sacramento. That earned Peterson a spot on the A's 40-man roster and his first invite to big league spring training. At spring training, Peterson was one of the A's top hitters and one of the team's last cuts. He made a brief appearance at the big league level early in the year when Brandon Moss went on the paternity leave, and he picked up his first major league hit and made a game-saving play at first base defensively.
It has been a bit of a struggle for Peterson since he returned to Triple-A after that brief major league appearance. He had an 801 OPS in April, but that fell to 760 in May and 565 in June. He is 1-for-12 thus far in July. Peterson has walked 44 times in 71 games, but his strike-outs are up (77) and he may be pressing. He has still shown his value defensively and has run the bases well (nine stolen bases in nine chances). The A's like what Peterson offers, but if they need 40-man roster spots later this season, his could be in danger if he continues to struggle.
Status: Looking to get back on-track
31. Chris Bostick
Perhaps no position player in the A's system has done more to raise his stock within the organization this season than Bostick. Although already well liked by the team's front office, Bostick has made a case for being one of the organization's top prospects with his effort so far for Low-A Beloit. The 20-year-old second baseman has been one of the Midwest League's best hitters this year, posting a .311/.382/.519 line in 79 games through Thursday. Bostick has steadily improved his play throughout the year and could make his High-A debut by season's end.
Bostick's rise in profile has been dramatic, as he was a 44th-round pick just two years ago (to put that in perspective, the draft only goes 40 rounds these days). The native of upstate New York was a two-sport star in high school and didn't receive the attention from baseball scouts that players from warmer climates did. The A's signed Bostick away from a commitment to St. John's and he immediately made an impact by hitting better than .400 in a truncated professional debut with the AZL A's. Bostick had a decent season with short-season Vermont last year, but he was hampered some by injuries. This year thus far, Bostick has been healthy and he has displayed the ability to hit for average, work a quality at-bat and hit for power. He already has a double-double (11 homers and 17 stolen bases) and with six triples under his belt, Bostick is threatening to pull a Jermaine Mitchell special (double digits in doubles, triples, homers and stolen bases, while hitting better than .300).
Defensively, Bostick is still working off the rough edges, but he has shown the raw ability to be a solid defensive second baseman. The A's like to challenge their top prospects with promotions late in the season and Bostick could see some time with Stockton in August. Even if he doesn't, he will be a shoo-in to debut in Stockton in 2014.
Status: On the rise