Stock Watch: A's Barreto bashing out West

We're only two months into Minor League action, but it's already been a tale of two seasons for Athletics prospect Franklin Barreto at Class A Advanced Stockton.

April was a disaster for Oakland's No. 2 prospect. The 19-year-old batted .171 in the season's first month, producing just two extra-base hits in 19 games.

May was much better. Barreto busted out with a .326 average, racking up three homers and 10 doubles en route to a .908 OPS.

We'll tackle what's going right with Barreto in May, but first, let's delve into his lackluster April.

There's no denying it was a miserable month for the teenager. You can probably guess some of what went wrong just based on his age and backstory. For starters, Barreto is one of the California League's youngest players. He skipped over the Class A level. He's also in his first year with a new organization, coming over from Toronto in the massive Josh Donaldson trade this offseason. Stockton manager Rick Magnante indicated that pressure did affect him.

But it goes beyond that. Disappointing as April was, the offseason was actually where Barreto most underperformed. Magnante said the shortstop arrived to Spring Training in poor shape. The A's had to get him more time in the gym to get him into baseball shape, and that limited his spring at-bats. So not only was Barreto underprepared for Opening Day at the Class A Advanced level based on experience, but he also flatly wasn't ready for the season.

Despite that, Oakland still gave the 19-year-old the aggressive push to Stockton. According to Magnante, the move was more a matter of organizational philosophy than a reflection of Barreto's spring performance.

"When we identify what we believe is a prospect as an organization, we're fairly aggressive with the promotions of those guys," the Ports manager said. "To some degree, A-ball is A-ball."

So Barreto struggled, at times mightily. The good news is he has pulled himself out of that hole. May was an outstanding month for the shortstop, and he's only gotten better of late -- he's batting .389 in his past 10 games, with homers in two of his past three.

His physical talents stand out immediately. Physically, Magnante compares Barreto to Rafael Furcal -- at 5-foot-9, Barreto is compact and "quick-twitch," Magnante said. Barreto doesn't have quite the speed or arm of a young Furcal, but he can scoot a bit and has a plus arm.

"He's sturdy, he's strong, muscled," Mangante said. "There's acceleration in his first step. He's aggressive by nature. All those things are reminiscent of that kind of player."

The quick-twitch aspect of his physique shines most at the plate. His swing is compact, and he has the bat speed to catch up to any fastball. It's a line-drive swing, but he already has enough strength to drive the ball into the gaps with authority.

"He's aggressive, he's on the fastball," Magnante said. "When he hits it and barrels it, he hits it hard."

If it all comes together for Barreto, he could be a high-average hitter with some power, but there's a pretty big gap between present and potential. Barreto's to-do list developmentally at the plate is what you'd expect for a 19-year-old. His pitch recognition and selection has a ways to go, and Magnante thinks that will most influence how close he gets to his ceiling.

"There is power there, but power is only served by power frequency," Magnante said. "You talk about raw power -- hit it over the fence to right, center and left -- he shows those capabilities. Will his swing and ability to hit allow that power to have a frequency? That's the question."

Barreto is going to get every opportunity to prove he can play shortstop in the Majors, but there's a lot of growth left for him there, as well. He's made 16 errors in 45 games and has a .905 career fielding percentage, so he's still prone to mistakes. The fast twitch elements of his game give him a chance to remain at short, but Barreto has to show more to convince even his manager that he's a shortstop long term.

"It's too early to tell," Magnante asid. "He's a center of the diamond player, whether it's shortstop, second base or center field. I don't know for sure. Right now, our job is to develop him at what we feel is the most valuable position, which is shortstop.

"The old adage is if you hit a kid 1,000 ground balls, he will become a better fielder. I think there's truth in that. It's a function of working hard and making him consistent with his catching and throwing. Working on things like his conditioning and strength, getting a better first step, enhanced range and hope he can become that shortstop in the future."

Two hot…

Red Sox SS Javier Guerra, Class A Greenville: The Drive have relied so heavily on their young position prospects, it's about time they renamed the city Teenville. Guerra came into the year with less hype than teammates Yoan Moncada and Rafael Devers, but if you were going to hand out a team MVP award, Guerra might get it. The Panama native is hitting .305 with five homers and four steals through 40 games. After drawing just one walk in April, he drew 12 free passes in May. On top of all that, he rivals Deven Marrero for the highest defensive ceiling among Boston's shortstop prospects. If Guerra can learn to corral his aggressive approach -- and his climbing walk rate suggests he can and is -- he should rate as one of Boston's top prospects by year's end.

Astros C Jacob Nottingham, Class A Quad Cities: The 6-foot-3 catcher had the chance to play tight end at Arizona, so you'd expect power to be a part of his game on the diamond. He's brought that and more in his full-season debut, leading the Midwest League with a .242 isolated power. The 20-year-old backstop struck out in 27 percent of his plate appearances last year with Rookie-level Greeneville. This year, he has that rate down to 19.6 percent. That's helped him hit .327 through 40 games.

Nottingham has work to do defensively but has caught 12-of-21 attempted basestealers this year. With the way he's swinging, he could emerge as one of the game's top catching prospects by year's end. Certainly, he's trending hard in the right direction.

…And one not

Cardinals OF Magneuris Sierra, Class A Peoria: You can't knock a 19-year-old too much for struggling in his full-season debut, but Sierra has failed to replicate his utter domination with the Cardinals' Rookie-level Gulf Coast League affiliate in 2014. After hitting .386 with 12 doubles and 13 steals last year, Sierra is hitting .195 with just five extra-base hits this year. He's only 4-for-9 on stolen base attempts and has an ugly 48-to-7 strikeout-to-walk ratio. The Cardinals' No. 6 prospect is an outstanding athlete who projects to hit for average and play solid defense in center, but his slow 2015 start has dashed hopes he might rocket through St. Louis' system.