Jim Callis

MLB Pipeline checks in from A's camp

Munoz, Healy among breakout candidates; Overton discusses comeback from injury

MLB Pipeline checks in from A's camp

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. will be visiting all 30 camps this spring. Today, we check in on the Oakland Athletics.

MESA, Ariz. -- Much like their big league club, the Athletics' farm system exists in a constant state of flux.

A year ago at this time, shortstop Addison Russell, outfielder Billy McKinney and shortstop Daniel Robertson were Oakland's top three prospects. Russell and McKinney went to the Cubs last season in a July trade for Jeff Samardzija, while Robertson was sent to the Rays in a January deal for Ben Zobrist. Three of the organization's best arms -- Nolan Sanburn, Seth Streich and Michael Ynoa -- also changed addresses in other transactions.

MLB Pipeline Spring Training Reports
Date Team
March 3 Red Sox
March 4 Blue Jays
March 4 Rays
March 5 Orioles
March 5 Twins
March 6 Braves
March 6 Pirates
March 9 Yankees
March 10 Phillies
March 11 Tigers
March 12 Nationals
March 13 Astros
March 16 Marlins
March 17 Cubs
March 18 Cardinals
March 19 A's
March 20 Mets
March 23 Giants
March 23 Brewers
March 24 Rockies
March 24 Angels
March 24 D-backs
March 25 Royals
March 25 Indians
March 25 Rangers
March 26 Reds
March 26 Dodgers
March 26 White Sox
March 27 Mariners
March 27 Padres

A's general manager Billy Beane's wheeling and dealing paid off with a third straight playoff appearance despite MLB's fifth-lowest payroll in 2014. He also made some trades that replenished the system, most notably the November shocker that sent Josh Donaldson to the Blue Jays for Brett Lawrie and three prospects: shortstop Franklin Barreto, right-hander Kendall Graveman and left-hander Sean Nolin.

"It's an innovative way that Billy has adapted to our circumstances," A's director of player development Keith Lieppman said. "Our whole philosophy has really sort of changed from homegrown to having players for a shorter window of time, creating value and trading for guys who can help immediately at the big league level. It creates more opportunity for players -- you could get an opportunity to play in Oakland like Sonny Gray or an opportunity with another club."

Camp standouts

Second baseman Joe Wendle, who was acquired from the Indians in a November deal for Brandon Moss, has made an immediate impression on his new organization. He has played in 15 of Oakland's 17 games this spring and has been one of its top hitters at .346/.414/.423. Healthy again after a broken right hamate bone wrecked his 2014 season, Wendle consistently barrels balls with his compact left-handed stroke.

"They love him up there in big league camp," Lieppman said. "They're very impressed with his maturity and his ability to play second base."

The A's had high hopes for several pitchers they drafted in 2013, but most of them were injured or ineffective during their first full pro seasons. Lefty Chris Kohler (supplemental third round) and righty Dustin Driver (seventh round) are healthy again, and they are back to where they were before missing all of 2014 with shoulder and back issues, respectively. Righty Bobby Wahl (sixth round) has looked steadier after command woes plagued him throughout last year.

Top Prospects: Wahl, OAK

"Bobby Wahl is making some noise with big velocity and a sharp breaking ball," Lieppman said. "He's been 93-95 [mph], and there's more in the tank. Last year, he couldn't get the ball over the plate to get ahead in the count, then he'd pitch up in the zone. Once he learns to use his excellent breaking ball, he'll be really good."

Breakout candidates

Shortstop Yairo Munoz was one of the most improved players in the system last year, hitting .298/.319/.448 as a 19-year-old at short-season Vermont after compiling a .618 OPS in two years of Rookie ball. The best athlete in the system, he has the tools to contribute in all phases of the game.

"He had trouble recognizing breaking balls last year, so on his own, he spent his own money a couple of times a week to have a local Dominican pitcher throw to him so he could practice his ability to hit breaking balls or take them," Lieppman said. "He really recognized his need to improve, and that shows his proactive nature. He's really tooled up. He was our best runner in short sprints the other day and has the best arm in our system."

Top Prospects: Munoz, OAK

Corner infielder Ryon Healy was one of the best all-around college bats available in the 2013 Draft, so his .285/.318/.428 numbers in the hitter-friendly high Class A California League last year were underwhelming. He didn't climb over the Mendoza Line for good until mid-May, but he batted .326/.356/.469 in the second half. The A's believe he'll continue to build off that momentum this season.

"After an abysmal start, he made a remarkable comeback," Lieppman said. "He put pressure on himself and tried to do too much. Once he began staying inside the ball and staying inside himself and stopped worrying about results, he put up very good numbers."

Top Prospects: Healy, OAK

Three questions with Dillon Overton

Heading into the 2013 season, it was Overton and not Jon Gray who was the Oklahoma pitcher scouts coveted the most. But while Gray soared to the No. 3 pick in the Draft by the Rockies, Overton hurt his elbow and had Tommy John surgery shortly after signing with the A's as a second-round pick. He made 12 abbreviated pro starts in the second half of 2014 and should be back at full strength this year. Did your elbow injury happen suddenly or was it something that built up over time? It seemed like you were throwing harder than ever in 2013, then you were sidelined.

Overton: It started hurting halfway through my junior year and was more gradual. It never hurt up until then. I started throwing in the mid-90s and I thought to myself, "When you peak suddenly like that, you can get hurt." That thought was in the back of my head and I didn't want it to be true, but that's what happened.

Top Prospects: Overton, OAK You returned last summer and your trademark command returned, with a 53/4 K/BB ratio in 37 innings. Were you worried during the comeback process at all?

Overton: As soon as you step back on the mound, the injury is always going to be in the back of your head. But I didn't struggle to get my pitches back at all. It's more a matter of velocity, of building my velocity back up, because I was at 88-91 or 92. This spring, they've told me my fastball looks a lot firmer than last year. How did the rest of your repertoire bounce back?

Overton: When I didn't have my velocity where it was before I got hurt, I had to pitch without speed and hit my spots. I had to throw my curveball and changeup more. My changeup is there every single day. When my velocity comes back, I'll be that much better.

Jim Callis is a reporter for and writes a blog, Callis' Corner. Follow @jimcallisMLB on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.