Arizona Diamondbacks prospect Brad Keller emerging for Kane County

On Tuesday night, I had the chance to check in on the Midwest League’s top second-half team, the Kane County Cougars as they hosted the Burlington Bees.  The Cougars have been hot since the break, and are in solid position to claim a spot in the Midwest League playoffs.  Kane County has been carried all season by a solid pitching staff which, even following the trade of Touki Toussaint to Atlanta in June, still has several interesting arms.

One such player is Tuesday’s starting pitcher, right-hander Brad Keller.  An unheralded 8th round pick out of Flowery Branch High School in Georgia back in 2013, Keller is putting himself on the prospect map in the Midwest League in 2015.  An intriguing mix of youth, size, stuff, and control, Keller figures to receive more national attention in the next round of prospect rankings.

One of the youngest players in his draft class, Keller signed for $125,000.  He hit the ground running in the Arizona League during his pro debut.  In 13 appearances, Keller went 56.2 innings with a 2.22 ERA while striking out 61 and walking 26.

In 2014, Keller bounced around the lower levels of Arizona’s system making three stops in total.  His overall line was weighted down by an unpleasant stretch with Missoula in the hitter-friendly Pioneer League where his overall line was inflated by an absurd .404 BABIP.  Overall, he went 71 innings with a 4.31 ERA while striking out 58 and walking 28. His 2014 growing pains saw him largely left off the industry's radar heading into this season.

Keller got his first crack at full-season ball this spring and has established himself as a pitcher to watch going forward.  Tuesday was Keller’s 20th start of the season, coming just one day after his 20th birthday.  In 114.1 innings, Keller has posted a 2.44 ERA and 1.17 WHIP.  His peripheral stats are strong as well.  Keller is averaging 7.01 K/9 and 2.20 BB/9, helping him to a solid 3.06 FIP.

Listed at 6’5", 230 pounds, Keller is an imposing physical presence on the mound. He works quickly and pitches aggressively, pounding the bottom of the strike zone with solid downhill plane. His delivery is smooth and efficient, allowing him to repeat his mechanics with impressive consistency for such a young pitcher. He is a good athlete despite his size and fields his position well.

Keller worked primarily off his fastball on Tuesday night and it was easy to see why. He sat mostly 90-92, regularly topping out at 93 and maintained that velocity for six innings. The pitch has solid sink and he uses his height to bury it in the lower part of the zone with regularity. He showed the ability to manipulate the baseball, generating good run when locating to the arm side and utilizing a straighter four-seam version when working to the glove side. Between the velocity, movement, and command, the pitch is clearly above average and could easily project to plus if he could work more consistently at his peak velocity.

The remaining developmental hurdles for Keller will come in the form of his secondary pitches. His curve showed from 79-84. He demonstrated some ability to spin the breaker, but struggled with consistency. The pitch was much better in the lower part of the velocity band. When he tried to throw the pitch harder and force the break, it flattened out and was ineffective. The makings of an average pitch are there, but he has some work to do.

Keller's change up also showed some promise, working in the low-80s and generating a couple empty swings. The pitch showed well in the bullpen during pre-game, but he did not use it much during game action. He cruised mostly on the strength of his fastball on Tuesday, but there is hope for a well-rounded arsenal at maturity.

Keller is essentially a pitch-to-contact type at this point in his development. His success is rooted in his ability to get ahead in the count, generate ground balls, and limit free passes. He is more polished than I anticipated. Given that he just turned 20, Keller has plenty of time to improve his secondary pitches and could even see a little velocity bump. Overall, there is a lot to like here. The profile, headlined by his sinker and command, is not that of a front line arm, but could work at the back of a rotation or in the bullpen.