Kevin Kiermaier’s Continuing Development in the Major Leagues


Kevin Kiermaier‘s opportunity to earn regular playing time for the Tampa Bay Rays is right now. With Wil Myers and Brandon Guyer both on the disabled list, the Rays are prepared to give the 24 year old outfielder the chance to show what he can do. The results, so far, have been quite impressive. Kiermaier’s defense has always gotten first billing, but he has also drilled two home runs and a triple in his 23 big league plate appearances, hitting .304 overall. On Tuesday, he hit leadoff for the first time, and he has the ability to hit there more often. But while Kiermaier has played well, his time with the Rays has also highlighted the places where he requires additional work.

It stands out that Kiermaier has now struck out nine times without a walk this season in the major leagues, and that is not a case of him working great at-bats but not finishing them with bases on balls. Despite not being a major power threat, Kiermaier has swung and missed excessively at all types of pitches. Brooks Baseball notes that Kiermaier has whiffed at a far higher rate than the league average against fastballs, offspeed pitches, and breaking stuff. Kiermaier has delivered several big hits against fastballs and shown the ability to drill them when they are left in hittable spots. On the other hand, he has been extremely aggressive, swinging almost every time he sees a fastball in the zone, and has been overwhelmed when the opposing pitcher reaches the mid-90’s.

Against other offerings, meanwhile, Kiermaier hasn’t done anything. He has swung way too often at pitches that have not been close and has only rarely made contact. He has especially struggled against breaking pitches, swinging nearly three times as frequently when they have been outside the strike zone and whiffing on 78% of his swings overall. With Kiermaier showing that type of weakness, teams are eventually going to stop throwing him fastballs anywhere near the zone until he proves that he can hit their breaking pitches. It’s like a Wil Myers situation all over again, but Kiermaier lacks Myers’ bat speed and power.

Can Kevin Kiermaier overcome these difficulties? Has his big league time demonstrated that he will never be a reliable hitter in the long-term? Before we jump to conclusions about Kiermaier’s future, we have to remind ourselves of two things: these numbers are all from just 23 plate appearances, and his development remains ongoing. Kiermaier is a prospect seeing extended time in the major league for the first time. It is understandable that he would be antsy, and we have to think that his at-bats will only continue to improve. Kiermaier will take more pitches and lay off more breaking balls, and he will go back to being the hitter that struck out in just 16.0% of his plate appearances the last three years in the minors.

In addition, while pitchers will change their approach against Kiermaier, he is also going to make an adjustment against them. The well-known adage is that you bring a hitter up to the major leagues when he can hit the fastball, and then you teach him to hit the breaking ball. That seems to be the situation with Kiermaier right now, and the best way for him to improve against big league curveballs and sliders is to see them firsthand. Kiermaier has never before seen the high-quality secondary pitches at the disposal of major league pitchers, but the more he sees, the easier it will be to recognize them and square them up. If Kiermaier never adapts, he will end up as a Sam Fuld-type player. After how many steps forward he has taken the last few years, however, there is reason to believe that he can keep improving.

Kevin Kiermaier has his flaws, and major league pitchers are going to exploit them. In a month, it is unlikely that he will still be hitting .300 with power if he is still in the major leagues. However, even if he does get worse, his struggles will be a valuable experience as he hopes to reach his potential at the plate.