Oakland A's prospects Daniel Robertson, Matt Olson, Boog Powell, Tanner Peters, Austin Hosue and Drew Granier will be suiting up for the Mesa Solar Sox this fall during the prestigious Arizona Fall League. The league begins on October 7. The Solar Sox will make their home at Cubs Park, the Cubs' new Arizona home in Mesa.
All three of the A's AFL position players have spent time on the High-A Stockton Ports' roster this season. The playoff-bound Ports currently have the best record in the California League.
Shortstop Daniel Robertson enters the AFL as arguably the A's top prospect. In his second full professional season, the 2012 supplemental first-round pick is batting .312/.404/.475 with 35 doubles, 15 homers and 70 walks.
The 20-year-old Southern California native played well during his first year-and-a-half as a professional, but he has taken big strides forward in 2014 with Stockton. Robertson has shown excellent bat control and the ability to work the count at the top of the order. He has also started to turn his line-drive power into homerun power. That power should continue to develop for Robertson has he progresses as a player.
Defensively, Robertson has continued to flash plus range and a strong arm at short. Robertson doesn't run all that well, but he has excellent foot work defensively and should be able to stay at the position long-term. He has also seen some time at third base and second base and could get playing time at both of those secondary positions this fall.
First baseman Matt Olson was the A's third first-round pick in 2012 (behind Robertson and former A's top prospect Addison Russell). Olson, like Robertson, has shown significant improvement in his second full professional season. In 2013, Olson had a solid campaign with Low-A Beloit, hitting 23 homers and driving-in 93 in the pitcher-friendly Midwest League.
Olson batted only .225 with a .326 OBP in 2013. This season, he has raised his average to .255 and his OBP to an impressive .398. He leads the California League in walks (111) and homers (36) and is seventh in slugging and sixth in OBP. Olson was named to the league's post-season All-Star team.
Olson is 6'5'' with long arms. Because of that build, he will likely always be vulnerable to being tied up inside, but when he can get his arms extended, Olson can hit the ball as far as anyone. He has done a good job of making adjustments to improve his plate coverage and he has also improved his plate discipline, an area that was already a strength coming into the year.
The 20-year-old Georgia native isn't fleet-of-foot, but Olson has soft hands and a strong throwing arm. He fields his position well at first base and has gotten his feet wet as a corner outfielder this season. Olson projects as a future first baseman, however. In many ways, Olson is a left-handed Chris Carter with a better glove.
Outfielder Boog Powell joins the Mesa roster after a frustrating second half of the season. The 21-year-old Southern California native had a dream first half, hitting .335/.452/.429 in 69 games with the Beloit Snappers. He won the MVP award in the Midwest League All-Star game and earned a mid-year promotion to High-A Stockton.
Upon joining the Ports, Powell continued to rake, collecting 19 hits in 48 at-bats. He was batting .396/.463/.500 in 11 games for the Ports before he was suspended for 50 games for testing positive for an amphetamine. His suspension should come to a close in the coming days.
The suspension aside, Powell opened a lot of eyes for positive reasons this season. He was always a player with a good eye and above-average speed, but this year he pushed his game to another level by adding some gap power. He will never be a homerun hitter, but if Powell can hit for enough gap power to keep defenses honest, he could present opposing teams a lot of problems. He is a slasher at the plate and he uses the whole field well. Powell is also an excellent bunter, and he takes advantage of his speed to beat out bunts and infield grounders.
Defensively, Powell has flashed an above-average glove in centerfield. He has a strong arm and the ability to cover a lot of ground in the middle of the outfield.
One area Powell figures to get work this fall is with his base-running. Despite his speed, Powell has just 35 stolen bases in 57 career stolen base chances. That percentage should improve over time if he can develop a better read on opposing pitchers' moves to the plate.
The A's will have four pitchers on the Mesa roster, although only three of those pitchers have been announced thus far. Right-hander Tanner Peters will be pitching in the AFL after missing much of this season with a shoulder injury. Throughout Peters' career, he has been effective when healthy, but he has struggled to stay on the mound.
This year, Peters opened the season on the Midland RockHounds' roster. He made three starts for Midland before landing on the DL, allowing seven runs in 17.1 innings. He has been rehabbing in Arizona for the past two months and returned to the mound on a rehab assignment in the Arizona Rookie League on August 6. He had two rough outings at the start of his rehab stint, but Peters has been effective in short outings since then.
When healthy, Peters draws similarities to former A's right-hander Justin Duchscherer. Peters doesn't have Duchscherer's plus cutter, but Peters does have an excellent over-hand curveball and an above-average change-up. Peters also developed an effective slider during the 2013 season. His fastball rarely tops 91 MPH, but he spots all of his pitches well to both sides of the plate. Peters can be prone to the longball, but he rarely walks batters and has struck-out nearly a batter an inning during his minor league career. He will be working this fall to make-up for the innings he lost this season to injury.
Right-hander Drew Granier has been a workhorse throughout his minor league career. Granier was the RockHounds' Opening Day starter this season, but he has had an up-and-down campaign. He was recently moved from the starting rotation to the bullpen.
Granier led the Cal League in strike-outs during the first half of last season, but since jumping to the Texas League midway through last year, his strike-out totals have dipped significantly. He has also struggled to keep his walk totals down, something that has plagued him throughout his minor league career.
Granier has intriguing stuff. He has a swing-and-miss curveball and a solid slider. His change-up is behind those two pitches, but it has shown promise at times. Granier's fastball sits in the low-90s and can touch 94. He gets good movement on his fastball, but sometimes that movement is too good, and he can't locate it.
Given Granier's command issues, his future may be in the bullpen, where he can limit his focus to shorter stints and where his curveball might be an even more effective weapon. With 125 innings already under his belt, Granier probably won't be given a huge workload (innings-wise) this fall.
Right-hander Austin House is coming off of a stellar season as the Stockton Ports' closer. The New Mexico alum has 19 saves for the Ports and a 3.64 ERA. He has a 79:19 K:BB in 54.2 innings and 2.24 GO/AO. House spent a week with Sacramento earlier in the year and didn't allow a run in seven innings of work.
House's fastball sits in the low-90s, but he gets good movement and sink with the pitch. He has used his fastball to get ahead of hitters all season. Once ahead in the count, House can go to his plus change-up for swings-and-misses, as well as a solid slider.
The Mesa squad will also include prospects from the Cubs, Nationals, Angels and Blue Jays organizations. Russell, who suited up for the A's in the AFL last season, will re-unite with some of his former teammates on the Mesa squad this fall. Sacramento River Cats' hitting coach Greg Sparks will serve as the Mesa hitting coach.