Every Spring Training, prospects get a chance to show what they can do as they prepare for the season ahead. Some are competing for jobs in big league camp, others are prepping for the season as they vie for spots at Minor League affiliates up and down a team's system. MLBPipeline.com will be visiting all 30 camps this spring. Today, we check in on the Oakland Athletics.

MESA, Ariz. -- A year ago, the Athletics' farm system was rich in infielders but not much else, especially pitchers. Midsummer trade acquisition Sean Manaea was the only hurler among the top eight prospects in MLBPipeline's Oakland rankings, and Dillon Overton was the only homegrown arm in the top 10.

• A's Top 30 Prospects list

:: MLB Pipeline Spring Training reports ::

Much has changed in the past 12 months, with pitchers now claiming seven of the first nine spots on our new A's Top 30 Prospects list. Six of them have joined the organization since last June, with right-hander Daniel Gossett the lone exception.

"We didn't really have any quality starting pitchers at Double-A or Triple-A at the start of last year, with the exception of Sean Manaea," Oakland farm director Keith Lieppman said. "Since then, with the Draft and our trade with the Dodgers and a lot of our guys stepping up, we've repositioned ourselves pitching-wise. We have a number of good young arms who are headed in the right direction."

Last June, the A's spent their first three Draft picks on left-hander A.J. Puk (first round) and right-handers Daulton Jefferies (supplemental first) and Logan Shore (second), all college products who sit near the top of the current Top 30. So do righties Grant Holmes , Frankie Montas and Jharel Cotton , all of whom arrived in a July trade that sent Rich Hill and Josh Reddick to the Dodgers.

Puk, who was a candidate to go No. 1 overall to the Phillies before Oakland landed him at No. 6, has the highest upside of the group. At his best, he works in the mid-90s with his fastball and backs it up with a wipeout slider, though he also has a history of inconsistency with his mechanics and command. The A's already have made some minor adjustments to Puk's delivery, and they like what they've seen so far.

"We don't usually do a lot with first-year guys," said Gil Patterson, Oakland's Minor League pitching coordinator. "But he was very open-minded. His right knee doesn't collapse now, which helps him repeat his delivery. Before, in college, it did quite a bit. His progress delivery-wise has been very good."

• Q&A with Logan Shore

Cotton, who has an exquisite changeup, is a lock to make the A's Opening Day rotation, and Montas also could break camp with the club after missing most of 2016 with rib issues. Gossett also is on the verge of making it to Oakland after shaking off a rough 2015 in low Class A to advance to Triple-A last year.

"Gossett struggled in his first year, but he started pitching down in the zone and sequencing his pitches better," Lieppman said. "The stuff has always been there, but he was pitching at the thigh and at the belt and he got beat up. Things started to happen for him last year and the system had lots of openings for performance, so he did well and was able to move quickly."

Camp standout

The A's best prospect also has been their best hitter in big league camp. After going 5-for-28 (.179) -- albeit with three homers -- in his introduction to the Cactus League a year ago, middle infielder Franklin Barreto has gone 9-for-19 (.474) with a triple this spring.

The baby of Oakland's camp at age 21, Barreto already has conquered Double-A and should be by far the best part of the four-player package the A's received from the Blue Jays in exchange for Josh Donaldson in November 2014. Though Barreto is more likely to wind up at second base than shortstop, his advanced hitting ability, promising power and solid speed could make him an All-Star there.

Breakout candidates

Jefferies' hot start at California last spring put him in position to go in the top half of the first round, but then he missed two months with a shoulder strain in March (which the Bears initially reported as a calf strain). Though he's a 6-foot right-hander who comes with some durability questions, the 21-year-old also impresses with his changeup and command of a low-90s fastball.

"He's a special man first, but he's a special pitcher and special athlete too," Patterson said. "He has a changeup with big bottom, life to his fastball and command. I hate to compare guys, but he almost reminds of Zack Greinke."

One of the most exciting athletes on the international market last summer, outfielder Lazaro Armenteros signed for $3 million, the largest bonus Oakland has given a foreign position player. The Cuban is still just 17 and remains quite raw, but he could offer plus power, speed and arm strength once he refines his tools.

"He's so physical at this age," Lieppman said. "He's really, really developed. He's one of those guys who's very confident in himself. You can see his talent. He has a presence about him. You don't see many 17-year-olds who look like this."