Rookie Hitter Evaluations (in small samples!)

Notes on Corbin Carroll, Gunnar Henderson, Anthony Volpe, Miguel Vargas, and more

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Now let’s talk rookies! All stats entering Thursday.

Corbin Carroll, OF, Diamondbacks

There were some early frustrations with Carroll hitting low in the Arizona lineup, but he was moved up to third on Wednesday. That’s a good sign, as are his 4 homers, 7 stolen bases, .887 OPS, and 134 wRC+.

Carroll is once again in the 100th percentile sprint speed, and there’s legitimate 50 SB upside for him as a rookie, but we already knew he was fast. What we wanted to confirm post-’22 was that he had the potential to do damage upon making contact.

Carroll only registered a maxEV of 107.5 mph last September, but that should never have been a worry for fantasy managers. maxEV is an opportunity stat and Carroll consistently ran high ISOs in the minors, even if he admittedly played in some outrageously hitter-friendly environments. We’re now 3 weeks into 2023 and Carroll has already hit a ball 111.1 mph.

Another early “concern” for Carroll has been his lack of walks. His 36.5 O-swing% isn’t ideal, but it’s also a stat that trends positively for many rookies, with Bobby Witt Jr. as a recent example. Of all the rookies to possibly be worried about at the moment, Carroll (also known as real life Pete Wheeler) shouldn’t be one of them.

Gunnar Henderson, SS/3B, Orioles

It’s been a bumpy start to the season for Henderson, who checks in with a .176/.373/.275 triple slash line entering Thursday. Through 67 plate appearances the 21-year-old is walking at a 22.4% clip (100th percentile in the league), but he’s also striking out an alarming 34.3% of the time.

Diving deeper into his plate discipline, Henderson isn’t chasing, which is good, but he’s actually not swinging much at all:

There are some really great hitters on that list, so this isn’t a bad thing on its own, but I also can’t help but wonder if he should be more aggressive right now. Not chasing is good, but so is swinging at pitches in the strike zone. Calculating zone minus chase swing% is a better predictor of OPS than just chase% (which is more used for OBP).

To me, this is an approach change that’ll take place over time. The fact Henderson debuted last season and was a consensus top-2 prospect all offseason made me forget he’s still just 21.

It might be a tough pill to swallow for those who took the plunge on Henderson in redraft this spring, but this is already shaping up as the type of rookie “letdown” who I want to be in on entering Year 2. But there’s still plenty of season left.

One final note on Henderson is that he has started 15 of Baltimore’s first 18 games, including 5 of 7 against lefties. He has hit higher higher than 5th just once.

Jordan Walker, OF, Cardinals

Here’s the good news:

• 96th percentile maxEV

• 93rd percentile sprint speed

• 97th percentile arm strength

Walker is a physical freak, but you probably already knew that. It’s still encouraging to see that his tools hold up as excellent in the majors. He doesn’t turn 21 until late-May, after all.

Walker made headlines for beginning the season with a 12-game hitting streak, which tied him with Eddie Murphy of the 1912 Philadelphia A’s for the longest by a player age 20 or younger.

Since that shine has worn off some minor concerns have surfaced. To be clear, these aren’t long-term concerns as much as they are impediments to his immediate success. For all of these rookie hitter breakdowns we aren’t trying to make judgements on their career-long prospects. We’re more trying to get a sense of where they’re at right now, and where they could be by the end of 2023.

Anyways, unlike Henderson, Walker is swinging a lot. Among qualified hitters he has the 14th highest chase rate, and the 5th highest swing% overall. This had led to a bottom-10 swinging strike rate, so I’m worried his 23.9 K% will begin to grow.

For him, it isn’t as simple as he’s getting unlucky and all the underlying stuff looks good. Right now, things don’t look good, and the Cardinals’ outfield/DH situation has only gotten more crowded since Alec Burleson was recalled.

Walker is undeniably talented enough to turn things around in a moment’s notice. All of my worries could look silly by Memorial Day, and that’s why I’m not willing to take too strong of a stance against him. Preseason expectations might need to be adjusted, however.

Anthony Volpe, SS, Yankees

Including Thursday, Volpe has led off for New York in 6 of their past 8 games. He enters the day slashing just .204/.338/.315 with some weak batted ball numbers:

These “lollipop sliders” as Jeff Zimmerman referred to them as certainly shouldn’t be taken too seriously, but a few of them are at least helpful for understand a player’s skill set.

The fact that Volpe is walking this much is everything for me. Without that I’d be hyper concerned with his profile. Not only does his 16.9 BB% bode well for his future, but in the interim it has helped him to take advantage of his “vault jump” and swipe 8 bases in 8 attempts.

Still, he has just 1 HR and 2 RBI. At a certain point the production will need to pick up for him to even reach his rookie year upside (which isn’t as high as his career-long potential, of course). Keep Volpe plugged into roto lineups for now, and continue monitoring his hard-hit data and maxEV (which currently sits in just the 23rd percentile).

Triston Casas, 1B, Red Sox

A big part of why I was so bullish on Casas entering ‘23 was that in his September cup of coffee he had a brutal .208 BABIP, but with excellent plate discipline and a strong .211 ISO. Positive regression felt likely now that he had gotten a taste of the bigs.

Unfortunately, he came into Thursday with an even-worse .152 BABIP this season, and the plate discipline had evaporated. His BB% has fallen and his K% has risen. So what gives?

Digging into his swing decisions, Casas is being more aggressive this year, and it isn’t the good kind with his chase rate rising from 21% to 33.3% in 2023. Each season is dealing with a ridiculously small sample, but just based on the results it appears that being more selective would do him favors.

Casas’ level of chase still isn’t bad (Baseball Savant has him in the 47th percentile), and when you watch this guy make contact it’s so evident there’s monstrous power coming. I’m very willing to be patient with the 23-year-old, who should become more selective throughout the year. He should also benefit once the warmer weather arrives to Fenway.

Miguel Vargas, 2B, Dodgers

Vargas dealt with a thumb issue during spring training where he literally couldn’t swing the bat. He still drew a number of walks, and that discipline carried over to the regular season as the 23-year-old checks in with the lowest chase rate (16.9%) in the majors.

That’s one of the only positives in his profile at the moment. Vargas has yet to homer or steal a base, and he isn’t hitting the ball particularly hard (though he has under performed his xBA and xSLG according to Savant).

I can’t help but wonder if that thumb is still bothering him. Vargas is still walking a ton, entering Thursday with a 21.9 BB% and an 18.8 K%. Is he trying to take it easy while his thumb heals? If so, why is he playing at all?

Another oddity is that his sprint speed is down from 29.3 ft/s last season (94th percentile) to 27.4 ft/s in 2023 (63rd percentile). This is a player who was a third baseman in the minors, played primarily first base with the Dodgers in ‘22, and all of a sudden became the everyday second baseman - a far more athletically demanding position.

It’s all so strange, but in some ways encouraging, and also disappointing for fantasy managers who expected a floor of league-average production with the upside for more. Unless something changes this weekend it’ll be tough to confidently start Vargas until he shows more.

Josh Jung, 3B, Rangers

I always found it strange how much weight some put on Jung’s time in the majors last year. He suffered a left shoulder strain in mid-February, missed basically all of the year, and was rushed into a major league debut down the stretch. It never surprised me that his plate discipline was all over the place, and it notably improved throughout his time in Texas:

So far in 2023 Jung is chasing less while swinging in the zone more frequently. It’s exactly what you want from a young hitter, who is now slashing .284/.342/.463 with 3 HR and a 128 wRC+.

He’s been fantastic for fantasy managers who waited at third base this spring. Jung was known for his power and hit tool combination coming through the minors. Now healthy, that’s exactly what he’s showing with the Rangers.

Ezequiel Tovar, SS, Rockies

Unfortunately, we aren’t ending on a positive note.

I was surprised that Tovar never received much hype throughout the spring, considering his top prospect status combined with the Coors factor. However, it turns out the market was right not to push him up draft boards as the 21-year-old is slashing .190/.254/.259, a line that’s 72% worse than league average.

Unlike Volpe, Tovar isn’t walking or stealing bases to salvage his fantasy value. In fact, Tovar is still searching for both his first homer and his first stolen base of the year.

In my “dynasty shortstop rankings takeaways” piece from January I cautioned that fantasy managers should expect growing pains with a young bat who entered ‘23 with just 14 career games above Double-A (and just 80 above High-A). It’s obviously fine to remain patient in dynasty leagues, just like it’s okay to move on in redraft formats.