Analyzing the MLB Rookies - 2023 Fantasy Baseball Prospects

February 17, 2023

Jon looks into the popular fantasy baseball rookies and top MLB prospects to consider for 2023 drafts. These fantasy baseball prospects can be impact players.

One great way to win your fantasy league is to get your hands on the MLB rookie of the year. Julio Rodriguez and Michael Harris II were two of the biggest keys to success last year, as they went on to return first-round value after being very cheap to acquire on your fantasy team.

There are plenty of fantasy baseball prospects and rookies being drafted right now, and there will be plenty more to make an impact on the game later on in the season after they get the call-up. Most of the players we talk about here do project to make the Major League team out of Spring Training, so we will have to make some decisions on them on draft day.

There are a lot of prospects to potentially talk about, and I'm sure I won't be able to get to them all, but let's go ahead and see how many we can rattle off today! The goal here is to get a better feel about the proper approach to each rookie. This is very challenging, obviously, since we have seen very-little-to-none of these guys in the Majors - but we have lots of minor league data to get into as well, so let's do that.

The Expensive Ones

Gunnar Henderson, Baltimore Orioles

Gunnar goes in the top 100 picks and he is the eighth third baseman off of the board in the average draft. The position is very thin after the top handful of names, so Gunnar is a pretty important name to have a stance on when draft day comes.

He is listed as the game's #1 overall prospect, so he is the poster boy for rookie players in 2023. Last year, he saw 498 PAs between AA and AAA and did this:

.300/.418/.536, 19 HR, 22 SB, 22.7% K%, 15.7% BB%

He go the call-up on August 31st and saw 132 plate appearances in the Majors:

.259/.348/.440, 4 HR, 1 SB, 25.8% K%, 12.1% BB%

What stands out most about Henderson is the plate discipline. You can see that he maintained a strong walk rate in the Majors while keeping the strikeout rate at a manageable level. He doesn't swing a ton (41% vs. a league average of 48%), which will raise a walk rate, but he also does a great job with his swing decisions (77.5% vs. a league average of 68.8%, 15th-best in the league last year). That swing decision metric is what percent of your swings are at pitches in the zone, so it's a good sign to be well above league average there.

He's clearly a mature hitter, and he hits the ball very, very hard (54% hard-hit rate last year). The knock on him is that he hit a ton of balls on the ground last year at 57%. That's one of the highest ground-ball rates in the league, and if it maintains like that, he will have trouble getting into the twenties for homers. There is good news there too because it wasn't a part of his minor-league profile - the marks were much better down there.

So we have a guy that swings the bat extremely hard and clearly knows what he's doing at the plate - this is a very impressive profile and I think I'm leaning towards buying in on him.

I still think my ideal approach to third base is to get one of Jose Ramirez, Manny Machado, Rafael Devers, or Austin Riley in the first two rounds - but if I miss the boat there, I am happy to take a shot on Henderson for 2023 - we could very well see him being a first-rounder next season.

Verdict: Not a priority at 3B, but a pick I am happy to make.

Corbin Carroll, Arizona Diamondbacks

Carroll is the game's #2 overall prospect right now, so he and Gunnar are in very similar positions here. Carroll slashed .303/.422/.604 in 434 minor league PAs last year with 23 homers and 31 steals. He recorded the second-highest max sprint speed (Tim Locastro) in the league last year, so it would seem that we have the floor here of a guy that will at the very least steal you a bunch of bases. I'm not going to worry about the fact that he attempted just three steals in 115 PAs last year - it's clearly a part of his game and he's way too fast not to be successful with the new rules going into place this year.

He doesn't quite have the raw power of Henderson with a 33% hard-hit rate last year in the Majors and a lower 5.5% Brl%. In the minors, he put up a 7.6% Brl% but a more solid 89.5 average exit velocity.

Carroll also had a higher GB% than you'd love to see at 48% - but it's far away from the danger area. I am less excited for Carroll than Henderson because I think he tops out around 20 homers, but a 40+ steal season with a good batting average and a lot of run-scoring is pretty likely, so I can definitely understand the pick, but Carroll is a top 75 player by ADP right now so it's a more costly pick to make.

Verdict: I am probably out due to the cost and lack of raw power.

Adley Rutschman, Baltimore Orioles

Not a rookie, but figured I'd throw in a few sentences here. Adley is being drafted as a top five catcher with an ADP in the top 70 right now. I am pretty much out on that given his low barrel rate (7.9%), lack of steals, and the fact that there are similar catcher options that go several rounds later (Willson Contreras, William Contreras, MJ Melendez).

Verdict: The upside and playing time is nice, but I like plenty of other catchers more at the price.

The Cheap Guys

Ezequiel Tovar, Colorado Rockies

Everybody gets a little more excited when the Rockies call up a hitting prospect, which they did last summer with Tovar. The shortstop hit .319/.387/.540 in the minor leagues with a 21% K% and an 8.5% BB%. He hit 14 homers and swiped 17 bags, both pretty solid numbers - but almost all of that came in AA. He spent very little time in AAA before getting the call to the Majors, and once he reached the show, he hit just .212/.257/.333 in 35 plate appearances.

We saw about 50 plate appearances where Statcast was tracking him, and the hardest-hit ball he recorded was 109.8 miles per hour. His hard-hit rate over the short time in the Majors was 33.3% - a low number.

The kid is just 21 years old and won't turn 22 until August. That means there is a ton of time for him to add power, but I don't see it happening this year. The only way it seems he could find his way to fantasy relevance is by stealing 20+ bags. His SB attempt rate last year was 20%, meaning about one of every five times, he had the chance to steal a base he went for it. That's a high rate but it's far from the elite (the highest marks are in the forties).

With Coors Field being a factor, you could see a .275 batting average and 25 steals if he plays all year - but that's a pretty rosy projection and it's far from a guarantee that the kid even starts the year with the Rockies.

Verdict: Completely out on Tovar this season.

Miguel Vargas, Los Angeles Dodgers

I have written up Vargas a ton already, so you can head over to my breakout hitters piece to read about him. I love his contact and power combination, and I love that he will have dual position eligibility.

Verdict: Vargas is one rookie I'm really in on at ADP.

Logan O'Hoppe, Anaheim Angels

He is a desperation pick at catcher. He goes right around pick 200 right now, which is quite high. We don't know for sure if he'll be the Angels' Opening Day catcher, so that is a key factor that we'll have to keep an eye on in Spring Training.

O'Hoppe skipped the AAA level, which could mean that they want to get him some time there before coming back to the Major League club. He hit well in AA, of course, with a .283/.416/.544 line with 26 homers and seven steals. He had a really great 17% K% and walked a ton at 16%. You can see why they were okay with him skipping AAA last season.

O'Hoppe turned 23 last week (happy birthday!), so I do think we'll see him spend most of the year in the Majors, it's just less clear how many games that will mean. He seems to have real power, and there's something to be said for that at the catcher position. I don't think I want to pay a top 250 pick for him, however, and I think he can be easily ignored in one-catcher leagues - but there's definite power upside here.

Verdict: Too many questions, too high of a price.

Triston Casas, Boston Red Sox

He spent most of the year in AAA last season and hit .273/.382/.481 with 11 homers and no steals (no attempts either). He got a call-up to the Majors in September and slashed .197/.358/.408 line, hitting five homers on a 7.5% barrel rate. The contact rate of 74% was right at the league average and he struck out just 24% of the time - another league-average figure.

The exit velocity stuff was a little bit more than middling with a 110.5 max, a 103.3 90th percentile, and a 90.7 average. The launch angle stuff looks promising as he regularly posted GB% below 40% in the minors - which is what you want to see.

Casas looks a lot safer than most of the names we're talking about today. He does not have a big strikeout problem, has at least average power right now, and can hit the ball in the air. He is also quite affordable at pick 240 - but will likely get some helium if the Red Sox come out and say he's their Opening Day first baseman.

Verdict: Casas feels safe enough to invest in as a late-round corner infielder.

Shea Langeliers, Oakland Athletics

Langeliers came to Oakland in the Matt Olson trade prior to the 2021 season, and now he looks like the Athletics' primary catcher with Sean Murphy also making his way to Atlanta this offseason. Langeliers spent most of 2022 in AAA, and there he hit .283/.366/.510 with 19 homers and five steals in 407 PA. We have minor league Statcast data on him, and there we see that he put up a strong 9% barrel rate with a low 22% K% and a nice average exit velocity of 89.8 miles per hour.

In the Majors, he hit six homers in 153 PA with a .218/.261/.430 slash line. The strikeout rate was high (35%), and that meant the Brl/PA was pretty bad (5.9%), but there is no doubt that there's some pop here.

He will need to make a big stride forward in contact (57.3% contact rate in the Majors, just 72% in the minors) - but if he does, he can definitely be a top 15 catcher or so even on that atrocious team out in Oakland.

Verdict: No need to worry about Langeliers in one-catcher leagues, but he's a nice deep-league flier.

Matt Mervis, Chicago Cubs

The Cubs went ahead and added Eric Hosmer and Trey Mancini this offseason, which was bad news for Mervis, who is now less likely to make the team out of camp. He figures to spend most of the year in the Majors, however, so he's someone we should be aware of for fantasy purposes.

Mervis spent significant time at three different levels last season:

That is 36 homers in 583 plate appearances, a homer every 16 PAs. Pretty good stuff there - and it came with an 18% strikeout rate. He was the only hitter in the entire minors with more than 35 homers and a strikeout rate below 20%. That gives him a pretty great chance to have an immediate impact at the Major League level - there is a lot of room for regression there.

Based on the signings the Cubs made and the fact that Mervis is not currently on the 40-man roster, he seems destined to start the year in AAA. That makes him tough to draft in standard leagues, but for deep leagues, he's someone to stash on the bench and he is definitely someone to add when he gets the call-up in all leagues.

Verdict: Avoid in standard leagues because of the playing time, but I want Mervis on my teams when he gets the call to the Majors.

Nolan Jones, Colorado Rockies

Jones is another guy that is more likely to start the year in the minors, but he would be pretty appealing if he does make the team. He played in the Guardians' organization last year and slashed .238/.356/.431 in AAA with 13 homers and 10 steals. That's not very good, but in the Majors, he did show a lot of raw power with a strong 8.6% Brl/PA and a 49% hard-hit rate.

The Rockies are strapped for talent, and with the injury-prone Kris Bryant and the aging Charlie Blackmon in the outfield, playing time certainly could open up for Jones. You always like to see a guy with some power in Coors since the environment there pushes batting averages up so much. Jones will certainly need the help as he struck out at a 33% clip in the Majors last year, so he will have to improve on that and benefit from some high BABIP to not kill a fantasy team's batting average.

Verdict: Jones is a bit of a long shot here, but he's someone to keep on your radar.

That'll do it for now. If you have other fantasy baseball rookies you're curious about, send them my way on Twitter and maybe we'll write a version two of this.

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