Analyzing Three New Rookie Starting Hitters

Baseball is back! It’s an exciting time when a trio of the toppest of top prospects will be in the starting lineup on opening day — Bobby Witt Jr., Julio Rodríguez, and Spencer Torkelson. That’s three of our top five overall prospects! There has been enough digital ink spilled on them, though, so let’s discuss three less heralded prospects who have earned a starting job.

I’m going to try a new format for this article, using bullet points to describe why I like the player and then why I don’t. Let’s dive in.

Jeremy Peña | HOU SS | #31 overall prospect

What I Like

• Massive power spike at Triple-A in 2021 (.311 ISO), driven by 37% HR/FB rate
• <Owns above average speed too and willingness to use it, with a 600 PA pace of 22.5 steals in 2021
• The Astros failing to sign either Carlos Correa or Trevor Story suggests their confidence in Peña
• He grades out as a plus defender, which should give him more of an opportunity to overcome a slow start at the plate or a mid-season slump

What I Don’t Like

• That Triple-A power spike came over a tiny sample of just 122 at-bats
• SwStk% has risen at each subsequent minor league level, driving up his strikeout rate to a professional worst at Triple-A
• He has stopped taking a walk, as his walk rate has been in freefall since Single-A in 2019
• His FB% plummeted at Triple-A, reducing the benefit of an insane 37% HR/FB rate
• Even with more grounders and fewer fly balls, his BABIP fell at Triple-A to the lowest mark since his 2018 debut in Low-A

Diego Castillo | PIT 2B/SS | #17 Pirates prospect

What I Like

• Those SwStk% marks! Since 2017, he hasn’t posted a mark exceeding 7.2%, so he could really make contact, driving a strikeout rate between excellent and elite levels
• Increasing walk rate and right around league averages, despite such strong contact ability. Often times you see low walk and strikeout rates as a hitter makes such good contact, he doesn’t even get a chance to take a walk and see four balls before putting the ball into play.
• He transformed into a fly ball hitter in 2019 and has maintained that fly ball tendency since
• His power surged in 2021, as his HR/FB rate went from the low single digits to double digits, while his ISO spiked from sub-.100 to at least .164
• He owns some speed, swiping about 12 bases over a 600 PA pace in 2021

What I Don’t Like

• He has run low BABIP marks over nearly the entirety of his minor league career, which will offset much of the benefits of a low strikeout rate on his batting average and OBP
• He’s on the Pirates, the team we project to score the second fewest runs scored in baseball, which will limit Castillo’s runs scored and RBI totals
• He figures to open the season batting eighth in the lineup, which isn’t ideal in any lineup, let alone the second worst lineup in baseball
• He’ll have to perform at least somewhat decently, as the Pirates are loaded with middle infield options, plus Oneil Cruz in the minors

Kevin Smith | OAK 3B | #23 Athletics prospect

What I Like

• A history of above average power in the minors, plus his highest HR/FB rate during his first year at Triple-A in 2021
• A surging walk rate that jumped into double digits for the first time at Triple-A in 2021
• A rebound in strikeout rate and SwStk% in 2021 after both increased dramatically at Double-A in 2019
• A fly ball tendency that makes the most of his home run power
• Speed and a willingness to use it – a 26 steal pace over 600 PAs using his 2021 Triple-A rate
• Given the obvious rebuilding efforts, Smith’s leash should be long, especially with few decent alternatives at either third base or shortstop

What I Don’t Like

• Lots of fly balls and a potentially high IFFB% could result in a low BABIP
• He’s on the Athletics, the team we project for the fewest runs scored in baseball, which will limit Smith’s runs scored and RBI totals
• He figures to open the season batting eighth in the lineup, which isn’t ideal in any lineup, let alone the worst lineup in baseball

Currently, my favorite is Jeremy Peña , simply because his playing time appears more secure at the moment and I’m willing to gamble on some of that massive power breakout being real. Also, he’s part of the best lineup by far, which will have a significant impact on plate appearances, runs scored, and RBI totals. Who’s your favorite of the trio?