Around baseball, the Rookie Leagues are all about development. Games are played with slightly different rules, with multiple coaching visits allowed in an inning and expanded rosters. Players receive significantly more one-on-one instruction during the Rookie Leagues than in other leagues.
The A's Arizona Rookie League squad is filled with players early in their professional careers. Many of those players hail from the A's Dominican Academy, while others were draft picks in 2010 and 2011. The roster will likely change throughout the season, as more draft picks sign with the organization.
The Arizona A's are managed by former Major League catcher Marcus Jensen. The Oakland native has skippered the AZL A's since the start of the 2009 season. He is joined by hitting coach Juan Dillone and pitching coach Ariel Prieto, the former A's right-hander.
The current AZL A's pitching staff is highlighted by right-hander Michael Ynoa, the Dominican pitcher who received a large signing bonus in 2008. Ynoa isn't likely to throw a lot of innings for the AZL A's. He is only 11 months removed from Tommy John surgery and is still building up his arm strength.
One starter who should get a significant number of innings is Andres Avila. The native of Mexico signed with the A's as an international free agent before last season, but had to split his 2010 season between the Arizona Rookie League and the Mexican Summer League. He will be in the US exclusively this season.
Left-hander Omar Duran made his first appearance this season out of the bullpen, but he should get a lot of work regardless of his role. The Dominican native was outstanding for the AZL A's last year, posting a 2.01 ERA and striking out 54 in 40.1 innings. He developed some elbow soreness during Instructs, however, so the A's have held him back from short-season Vermont for now. Duran, who signed as an international free agent before the 2008 season, has a plus fastball, but elbow issues have slowed his development thus far. He is still only 21 years old.
The other two southpaws currently on the AZL A's roster are Eric Potter and Kevin Rodriguez. Potter was the A's 19th round pick this season out of Maryland. He had a strong debut for the AZL A's, striking out six in 2.1 innings. Potter was a senior when the A's drafted him and, given that level of experience in good baseball conference like the ACC, he may not be long for the Arizona Rookie League.
Rodriguez is debuting in the US after two seasons in the Dominican Summer League. He threw only 10.2 innings in the DSL last season. Rodriguez has a solid breaking ball and a fastball that sits 88-91 MPH. He is the youngest pitcher on the staff, after Ynoa.
Aaron Larsen returns to the AZL A's after posting a 2.89 ERA in 37.1 innings last season. He also had two starts for the Low-A Kane County Cougars. The right-hander was a 34th round pick of the A's in 2010 and has a good command of the strike-zone.
Harvard alum and 2011 draft pick Max Perlman is making his professional debut in the AZL A's rotation. The 6'7'' right-hander threw 60 innings for the Crimson this season and had a 1.80 ERA. He also pitched well in the Cape Cod League last summer. Perlman could be promoted to Vermont early in the short-season if he pitches well for Arizona.
Jose Azor is making his US debut after spending three seasons in the Dominican Summer League. The Dominican right-hander had an 0.95 ERA 19 innings for the DSL A's last season. Azor was supposed to make his US debut last season but visa problems kept him in the Dominican. He has a good, hard sinker that can touch 94 MPH and a developing breaking ball.
Alexis Juma is another pitcher making his US debut. He spent four years in the DSL. He has an ERA of 2.00 for his last two seasons in the DSL, but he has only thrown a combined 51.1 innings.
Three 2011 draft picks round out the AZL A's pitching staff: Thomas Girdwood (28th round), Nate Eppley (round 29) and Drew Granier (round 32). Girdwood had a lot of success in college as a reliever, but was less successful this season in the rotation. He is likely to serve as a reliever for the AZL A's this year. Eppley is the younger brother of the Rangers' reliever Cody Eppley. Nate joins Ynoa and Perlman as pitchers on the staff 6'6'' or taller. Granier drops down, using a three-quarters delivery. He was a strike-out pitcher at Louisiana-Monroe as a starter.
The player with the highest international signing bonus from the A's in 2009 highlights the position player half of the AZL A's roster. Shortstop Wilfredo Solano makes his US debut after a season in the Dominican Summer League. The Venezuelan infielder hit only .179 last season for the DSL A's, but he walked 30 times in 45 games and impressed A's coaches during the US Instructional League. The 18-year-old is the youngest player on the team. He will get the bulk of the at-bats at shortstop, but will also likely see a few innings at second and third base.
Another player who will see time around the infield is Jensi Peralta, who was signed to a six-figure bonus before the 2008 season out of Venezuela. The 19-year-old is repeating the AZL after batting .223 last season. He is off to a fast start this year, with six hits – including two doubles – in his first 12 at-bats.
With the exception of 2011 39th round pick Shane Boras, the rest of the AZL A's infielders are from Oakland's Dominican Academy. Boras will be looking for some regular at-bats after he played sparingly during his career at USC. He is the only switch-hitter on the team.
Corner infielder Michael Soto has arguably the best power of the AZL A's infielders. He is making his US debut after an All-Star season with the DSL A's in 2010. Third baseman Luis Baez also had a strong season for the DSL A's last year, batting .282 with a 781 OPS in 52 games. Miguel Marte is the other corner infielder on the roster. He is repeating the Arizona Rookie League after hitting six homeruns in 241 at-bats last season (two for the DSL A's).
Middle infielder Franklin Contreras makes the jump to the US this season after a break-out campaign for the DSL A's in 2010, when he hit .284 with an 848 OPS. In two previous seasons in the DSL, Contreras never hit higher than .172. Jonatan Santana is the veteran of the group. He has been playing professional baseball since 2006, although this is only his second season in the US.
The outfield group is highlighted by a pair of top-10 draft picks for the A's this season, although at least one (Bobby Crocker) isn't likely to spend the majority of the season with the AZL A's. Crocker was the A's third pick (fourth round) out of Cal-Poly and he has enough polish to his game already that one would expect him to be challenged by the A's in the New York-Penn League before too long. Crocker has three hits in his first four at-bats for the AZL A's.
Dayton Alexander, the A's sixth-round pick, is likely to stay in the AZL for longer than Crocker. The Feather River Junior College outfielder is less polished than Crocker, but has five promising tools. Another raw outfield prospect with promising tools is Rashad Ramsey, who was taken out of a Georgia HS in the 20th round last season. Ramsey has well above-average speed, although he is coming off of off-season knee surgery to repair a torn meniscus. Despite being a 2010 draft pick, he is the second-youngest player on the team, having just turned 19 in May.
Kelvin Rojas and Rhett Stafford round out the list of AZL A's outfielders. Rojas, a native of the Dominican, returns to the AZL after making his US debut with the AZL A's last season. He spent three-plus seasons in the DSL before coming to the States and he showed decent power in the Dominican. Stafford was the A's 22nd round pick this season out of Marshall. Stafford displayed a well-rounded game in college, hitting for power and running the bases well. He caught, in addition to playing in the outfield, in college, but he is expected to see time in the outfield primarily in Arizona.
There are three catchers listed on the AZL A's roster, although one of those catchers isn't likely to play there much – if at all – this season: Josh Leyland. Leyland, a 2009 draft pick out of a Southern California high school, has battled back problems the past two seasons and has been playing at first base, rather than behind the plate, of late. Leyland showed prodigious power in high school and it will be interesting to see what he can do at the plate now that he is healthy.
Nick Rickles was the A's 14th round pick out of Stetson this season. He put up intriguing numbers at Stetson, homering four times as often as he struck-out. Rickles seems like a more advanced prospect than would normally start in the Arizona Rookie League, but the A's might be looking to separate him and fifth-round pick Beau Taylor (who is with short-season Vermont) so that both can get regular playing time.
Reynaldo Mateo should also see playing time behind the plate for the AZL A's this season. He is making his US debut after two seasons in the DSL. In 2009, he was the DSL A's best hitter by far, batting .364 with a 1042 OPS in 41 games. He slumped in 2010, batting only .236 with a 697 OPS in 56 games, but is off to a good start this season, having homered in his first game of the year. Mateo is a very patient hitter and he posted OBPs of .481 and .385 the past two seasons.