MLB is experiencing a new youth movement. Superstars like Juan Soto, Fernando Tatis, Jr. and Ronald Acuña, Jr. are grabbing headlines and making All-Star teams with their swaggering style of play. The new #LetTheKidsPlay campaign was generally met with applause (minus some exceptions). Baseball’s efforts to market itself to all those attention-deficit millennials will rely in no small part on this flashy new wave of superstars.
With all this in mind, here is a look back at MLB’s youngest players from 2019. The players here appear in order from youngest to less-youngest. To see their specific ages, click here.
Elvis Luciano holds the distinction of being the first MLB-er born in the 2000s, which automatically makes everyone reading (and writing) this article feel very old. Luciano is a fastball-slider reliever for the Blue Jays who debuted with 33 2/3 innings of 5.35 ERA ball last season. That’s bad, and there’s not really any reason to think he’ll be better next year. His peripherals and projections are unanimously non-optimistic about his performance. A below-average strikeout rate (17 percent) and an impossibly high walk rate (15.3 percent, around double league average) led to a sub-mediocre 5.56 FIP. Projection systems seem to think that he’ll spend most of 2020 in the minors, which is almost certainly for the best.
With all this in mind, however, please Don’t Be Cruel to Elvis (remember, he’ll be 20 [two-zero!!] in 2020). It’s only once in a Blue Moon a 19-year-old pitcher comes along, and baseball fans usually Can’t Help Falling in Love with crazy outliers like Luciano. Luciano was a Rule 5 pick, which meant that the Jays had to keep him in the bigs for the entire season if they wanted to keep him in their system at all. What he really needs at this point is some extra seasoning in the minor leagues. Hopefully, he’s able to polish up his repertoire and properly break out in a couple of years.
Vladimir Guerrero, Jr.
Hey, look, another Blue Jay! After spending some time “working on his defense” in AAA, Vladdy Jr. made his Major League debut in late April to much well-deserved fanfare. The Jays signed him as an international free agent all the way back in 2015, and he quickly established himself as the face of the Blue Jays’ farm system. Just watch this ridiculousness and succumb to the sweet, sweet hype.
— New Hampshire Fisher Cats (@FisherCats) May 7, 2018
So how did the most hyped prospect since Bryce Harper (and possibly ever) do in his first taste of the major leagues? He did… fine. He was a perfectly solid player who was worth a perfectly solid 2.1 bWAR in his rookie year. “Perfectly solid” is a perfectly solid thing to be, but that’s not what the Blue Jays (or the world) were/are expecting out of Vladito. They’re expecting the guy who spent his minor-league career raining white-hot dinger bombs on the hapless heads of pitchers across the minors. However, his somewhat underwhelming 2019 results aren’t any reason to give up prematurely (duh). Vladdy’s swing is still a joy to behold, and it’s very probable that the only thing he needs to do is get used to major-league pitching. It’s tough up there.
Even in the cold, emotionless world of computer projection systems, there’s excitement about the younger Vlad’s future. Steamer projects him to be worth 3.6 WAR in 2020. Baseball-Reference isn’t that excited, but an .809 OPS from a 21-year-old is still pretty crazy. Dan Szymborski’s indispensable ZiPS projections haven’t made it north of the border yet, but there’s no reason to think that they won’t be optimistic as well. So give the man time to settle in, and watch these clips until he does.
Adrián Morejon, San Diego’s seventh-highest-ranked prospect (by Fangraphs), tossed eight innings for the Padres last year. That is a perfect sample size for detailed and relevant statistical analysis. Unfortunately, Morejon got smacked around to the tune of a 10.13 ERA in his brief time in the bigs last season. ERA means less than nothing when dealing with sample sizes this small, though, so it’s worth looking at his peripherals and minor-league data to get a better picture of what kind of pitcher he can be in the future.
Basically, Morejon’s great when he’s not hurt. He racks up the strikeouts, doesn’t really give up any homers and (by all accounts) his changeup is pretty unfair. His fastball tops out around 97 and apparently he’s pretty good at mixing speeds with it. For a more complete scouting report, visit this link from two of baseball’s foremost prospect experts.
His biggest problem (besides durability) is control. Morejon’s walked 58 batters in his 173 1/3 innings of professional baseball thus far, which is a bit on the high side. It’s not a deal-breaker thanks to his high K-rate, but it’s an issue he’ll want to iron out if he wants to maximize his potential in MLB. And he’s still only twenty years old, so there’s plenty of time for him to get his mechanics up to major-league standards.
Another Padre! A pattern is beginning to emerge here. Muñoz fits perfectly into the Ricky Vaughn archetype of pitchers who throw 100-MPH missiles everywhere except for the strike zone. He’s touched 103 in his time in the minors and has struck out a ridiculous number of batters at every level of the minors. He even K’d 11.74/9 IP in his first taste of the majors last year, which is pretty crazy for someone who’s just barely old enough to drink.
The unfortunate caveat to all this triple-digit excitement is the usual one with young dudes who throw hard- he walks way too many guys. His 76 walks in 129 professional innings are simply too many, no matter how many hilariously bad swings a pitcher induces. A 101 MPH fastball and a K-rate of 12/9 IP will grant anyone a little extra leeway in re: control, but Muñoz’s current walk rate is a problem that can’t be ignored. He’s going to have to put in some pretty serious work on his command if he wants to stick in the big leagues.
At the end of the day though, the guy still throws some white-hot smoke (that doesn’t make sense, just go with it). It’s always easy to dream on that kind of velocity, and it’s not hard to imagine him becoming a valuable reliever if he can figure out his control issues.
Fernando Tatis, Jr.
The third consecutive Padre on this list falls into the Vladdy Jr. camp of über-prospects who were expected to make an immediate impact in the majors upon their callups. Unlike the Jays, however, the Padres committed themselves to put out the best Opening Day roster they could. Tatis, Jr. broke camp with the big club and became a superstar pretty much instantly. He racked up 4.2 bWAR in 81 games before a stress reaction in his back sidelined him prematurely. Those are serious MVP numbers.
Despite all the insane baserunning and massive dingers and diving catches, Tatis, Jr. has a few concerning question marks around the edges of his player profile. The most surprising of these is his subpar defense, which Ben Clemens focuses on in this informative Fangraphs article. Statcast’s new Outs Above Average metric (which rates defensive ability with a catch probability system) absolutely hated Tatis, Jr.’s defense. The Clemens article explains his problems very well, but the TL;DR version is that Tatis, Jr. had some pretty major problems with arm accuracy last season.
Apart from that, the only issues with Tatis, Jr.’s potential 2020 performance are regression-related. He slugged a hilarious .590 in 2019. That would be a stellar mark for a DH- it’s beyond ridiculous for a shortstop. His xSLG (expected slugging percentage, based on things like exit velocity, launch angle and sprint speed) was a full hundred points lower than his actual .590. That’s still great, but it’s not the absurdity that was his 2019 figure. Some regression should be expected come 2020. He also strikes out too much, but he was 20 years old in 2019. That issue will probably fix itself.
To conclude, that’s all for this little dive into MLB’s youth movement. #LetTheKidsPlay!
For any fans out there who might be interested, some of the pitching videos were taken from this YouTube channel. It’s an absolute goldmine for pitching enthusiasts. Be careful though- it’s a real rabbit hole.