Four MLB Players Set To Go From Good To Great In 2024
Image credit: (Photo by Brace Hemmelgarn/Minnesota Twins via Getty Images)
Baseball America readers are used to discovering which young players are good before they’re good. There’s something exhilarating about following a prospect since his rookie ball days and then watching him become a star in the majors.
What about players who have already debuted and have the skills to become great? We’ll refer to this as making “the leap.” Bobby Witt Jr. is an example of someone who did this last year.
For this exercise, we will exclude Corbin Carroll and Gunnar Henderson. Last season’s Rookie of the Year winners have already become superstars. We also covered Grayson Rodriguez last week, who fits this description.
Here are four more 2023 rookies who could take that next step this season.
Triston Casas, 1B, Red Sox
Now that minor league stats are more publicly available, it’s easy to spend too much time pouring over them. This is both a blessing and a curse. Production is good and can help us undercover underrated players that scouts aren’t impressed with. But we can also forget that players are sometimes working on specific areas of their game in the minors.
For example, Casas’ minor league stats weren’t as important as unearthing nuggets like this:
Casas’ raw power has been evident since his amateur days, and he likely wouldn’t have benefitted much from swinging out of his shoes in the lower minors. He was playing the long game, purposely chasing OBP over SLG leading up to 2022.
Interestingly, the start of his major league career mirrored his ascent of the minors. Casas debuted at the end of 2022, and showed a plus eye at the plate, but was overall too passive. Combined with some poor BABIP luck, he hit just .197 (though he posted a .358 OBP with five homers in just 27 games).
Casas was more aggressive to begin 2023. After he cleaned up some chase issues (in addition to overcoming more bad BABIP luck), he took off:
After posting a 59 wRC+ in April, Casas was an above-average hitter every month thereafter. He especially took off after the all-star break. Casas began the second half with homers in three straight games and finished as one of the best hitters in baseball (min. 200 PA):
It’s prudent to mention that full-season stats are more predictive than partial-season stats. But when you have a young player who made noticeable skill gains, we can treat it as a small amount of signal.
If Casas repeats his 2023 this season, then he’ll be a good player. If he comes close to repeating his second half, then he’s going to be a superstar.
Eury Perez, SP, Marlins
Like many fellow members of his rookie class, Perez arrived ahead of schedule in 2023.
Then again, that’s always been the case for the 6-foot-8 righthander out of the Dominican Republic.
In 2021, despite no prior pro experience, he was given a rotation spot at Low-A to begin the season. At just 18 years old, he made it to High-A by season’s end, registering a 0.88 WHIP and a .158 batting average against.
After posting a 26.0 K-BB% as a 19-year-old in Double-A throughout 2022, Perez returned to the level to begin last season. The Marlins saw enough after just six starts.
Miami managed his innings in the middle of the summer, but Perez totaled 91.1 big league frames in 2023. He logged a 3.15 ERA with a 20.6 K-BB%, but a peak under the hood reveals even more growth potential.
Among starting pitchers with at least 90 IP last season, only Spencer Strider and Tyler Glasnow had a higher swinging strike rate than Perez. Only five pitchers generated less contact on swings outside the zone. Just two (Strider and Joe Ryan) allowed less contact inside the zone.
Where Eury struggled compared to other SwStr% standouts was recording called strikes. This is backed up by his 98 Location+ (per Eno Sarris’ Stuff+ model) and a 36.6% ball rate.
Command is therefore something to work on, but that’s okay considering he doesn’t turn 21 until April 15. Perez can rely on his pure stuff in the interim.
No starting pitcher had a higher spin rate on his fastball than Perez, and only three averaged a higher velocity. Meanwhile, his slider averages an impressive 86.4 mph and his power changeup sits just under 90 mph.
It all came together on a mid-August afternoon at Dodger Stadium. Perez flashed immense upside on an economical 90 pitches, recording a 47% whiff rate (!!) while allowing just two hits over six scoreless innings.
After logging a combined 128 innings last season, here’s to hoping Perez can top the 150-inning mark in his sophomore campaign.
Royce Lewis, 3B, Twins
It’s impossible to not root for Royce Lewis’ story of perseverance.
The No. 1 overall pick in 2017 endured an uneven 2019 minor league season, falling from preseason No. 9 to No. 26 entering 2020. He lost that summer due to the pandemic and then tore his ACL in spring training, in 2021.
Lewis made it to the majors in early 2022, playing so well that Minnesota wanted to keep his bat in the lineup even when Carlos Correa returned from injury. They sent him to Triple-A to work on playing center field. He returned to the majors just 12 days later and re-tore the same ACL.
He then made it back to the majors exactly one year later and homered in his first game. Every time Lewis has been knocked down, he has come back stronger.
The 24-year-old also dealt with an oblique strain and a hamstring injury down the stretch last season. When on the field, however, Lewis has been spectacular.
Here’s a list of every rookie age 24 or younger since World War II who has hit at least 15 homers with a .300 average and a 150 OPS+ (via Stathead):
Lewis has slashed .307/.364/.549 with 17 homers and 57 RBIs across 70 games and 280 career MLB plate appearances. While he has overperformed his expected stats, Lewis has done all this with a strong 21.4 strikeout percentage. That suggests regression doesn’t mean he’s about to flop.
In addition to an improving chase rate during his time with the Twins, Lewis continues to rise to the moment.
In late 2023, he became “Mr. Grand Slam,” slugging four of them in a 20-game span. This included a stretch with seven homers in 12 games.
He then homered in his first two postseason plate appearances as the Twins won their first playoff game since 2004. Incredibly, both Lewis and the team weren’t sure if he’d play 24 hours before first pitch as he was recovering from his hamstring injury.
Many fans will be quick to point out his injury risks this offseason. They should instead be asking themselves what happens if Lewis remains healthy.
Bobby Miller, SP, Dodgers
As if the Dodgers needed a breakout candidate this season.
The 2020 first-rounder out of Louisville was limited to 56.1 innings in his 2021 pro debut due to an oblique injury, but he at least reached Double-A by the end of the year.
Miller spent 2022 between Double-A and Triple-A, totaling 112.1 innings. The 4.25 ERA was disappointing, but his peripherals were much better—a 3.68 FIP, a 23 K-BB% and 145 total strikeouts.
At this time last year, Baseball America’s Geoff Pontes noted that Miller had one of the best sliders among Top 100 prospects and one of the best overall pitch mixes.
This was backed up by Miller’s Stuff+ in his major league debut. Here’s the 2023 rookie class sorted by Pitching+ (per Sarris’ model):
From a top-level perspective, this shows us that Miller has a good pitch mix with above-average command. What makes him special, however, is that he throws five pitches at least 15% of the time—and they’re all plus pitches according to Stuff+.
Another way to view Miller’s arsenal is through Baseball Savant’s run value:
Interestingly, his slider graded out the worst of his offerings by this metric, whereas Sarris’ model considers it his best pitch.
Miller’s profile is enticing because his wide arsenal provides him options. That applies both on a per-start basis and for his overall development.
Compare this to another rookie arm like Taj Bradley, who needs to develop an entirely new pitch to fill out his arsenal, and it’s clear how close Miller is to a breakout campaign.
Like in the minors, Miller’s surface-level production with the Dodgers wasn’t as strong as his peripherals. He had a 3.76 ERA despite a 3.51 FIP. Perhaps a 71.3% left-on-base rate led to that disparity. Failing to strand runners was also a theme during his minor league days.
Entering the 2023 postseason, the Los Angeles Times wrote about how Miller learned to control his emotions after over-exerting himself at times as a rookie. It’ll be a focus for him in 2024 and beyond.
If there’s any organization that can help Miller bring it all together—tweaking his arsenal, using the best pitches in the right spots, fine-tuning his command, developing the mental side of pitching—it’s the Dodgers.
Adjustments may already be in process. After recording a 9.9% swinging strike rate over his first 13 starts, that number jumped to 13.4% over his final nine. Backed by arguably the best player development system in pro baseball, Miller might truly have it all entering 2024.
