10 Young MLB Players on the Verge of Becoming Superstars

Zachary D. Rymer@zachrymerMLB Lead WriterFebruary 8, 2018

10 Young MLB Players on the Verge of Becoming Superstars

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    Brace Hemmelgarn/Getty Images

    A new Major League Baseball season is getting closer every day. In these modern times, that means a handful of young players are that much closer to superstardom.

    According to FanGraphs' wins above replacement, the last three seasons have been the best ever for young (i.e. age-26-and-under) hitters. Young pitchers aren't keeping up, but it wasn't long ago that they had a historic season of their own in 2013.

    Today, we're out to answer a simple question: Who's next?

    Ahead are 10 young players on the verge of becoming superstars. The list follows most of the same rules—namely: no prospects, and MLB experience is a must-have—as our rankings for the 25 best players under the age of 25, and thus features some of the same names.

    Otherwise, the age limit is raised to 26 and there are two other stipulations: Players must not already be superstars, and there must be some reason to believe they can be better than they have been.

    Let's take it away.

Luis Castillo, SP, Cincinnati Reds

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    Justin Berl/Getty Images

    Age: 25

    As a prospect, Luis Castillo didn't land in a Baseball America top 100 until the middle of 2017, at which time he was already on his way to stardom.

    Castillo made 15 starts for the Cincinnati Reds and put up a 3.12 ERA with 98 strikeouts in 89.1 innings. This was after he'd already compiled a 2.58 ERA and 81 strikeouts in 80.1 frames at Double-A Pensacola.

    Pure lightning is contained within Castillo's right arm, as his 97.5 mph fastball was up there with Luis Severino's among the league leaders. He also features a devastating changeup that ranked fifth in whiffs-per-swing rate.

    The fact that Castillo walked 32 batters in his 89.1 major league innings bodes less well. Ditto for how he also gave up 11 home runs.

    But between his ultra-low 73.3 contact percentage and 84.7 mph exit velocity allowed, he's demonstrated he's not easy to hit. He figures to get even tougher to hit if he keeps putting more trust in his two-seam fastball, which moves as if it's bat-repellent. 

    A starting rotation spot is Castillo's to lose going into spring training. Assuming he picks up where he left off, he has the potential for a Severino-style breakout in 2018.

Jose Berrios, SP, Minnesota Twins

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    Jim Mone/Associated Press

    Age: 23

    Jose Berrios first arrived as a much-hyped prospect in 2016. Before long, he had everyone looking confused and asking, "Is that it?"

    His debut was...well, not pretty. The young righty pitched to the tune of an 8.02 ERA in 14 starts with the Minnesota Twins, striking out only 49 while allowing 35 walks and 12 homers in 58.1 innings. 

    His 2017 encore was better. As in, much better.

    Berrios threw the ball from a different angle, achieved by moving his position on the rubber and by lowering his release point. He also relied less on his four-seam fastball and more on his other pitches, most notably a filthy curveball made for buckling knees.

    These adjustments led to a 3.89 ERA over 145.2 innings. He picked up strikeouts at a higher rate (8.6 per nine innings) while allowing walks (3.0 BB/9) and home runs (0.9 HR/9) at smaller rates. Regarding the latter, it helped that he stifled hard contact by permitting a low 85.2 mph average exit velocity.

    In all, this is a young pitcher who's always had great talent and who's proved capable of adjusting as needed. These are qualities befitting of a budding ace.

Greg Bird, 1B, New York Yankees

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    Rich Schultz/Associated Press

    Age: 25

    From the shoulder surgery that sidelined him in 2016 to the ankle surgery that limited him in 2017, it sure seems like the injury bug has it out for Greg Bird.

    He is, however, healthy going into 2018. And when he's healthy, he hits.

    He showed as much late in 2015 when he debuted with an .871 OPS and 11 homers in 46 games. He did it again late last season after his return with an .891 OPS and eight homers in 29 contests. He then added three postseason long balls.

    Bird has the two things you want in a slugger: patience and a swing made for power. His 10.9 major league walk percentage is evidence of the former. Evidence of the latter can be seen in how both his ground-ball percentage (28.4) and hard-hit rate (40.6) are reminiscent of Joey Gallo's numbers.

    The lefty swinger also has a preference for pulling his batted balls. Factor that in with everything else, and he's a perfect candidate to hit ball after ball into Yankee Stadium's short right field porch.

    Assuming he can keep the injury bug at bay, Bird shouldn't lag too far behind Giancarlo Stanton and Aaron Judge in what should be an epic New York Yankees home run barrage.

Rhys Hoskins, LF, Philadelphia Phillies

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    Matt Slocum/Associated Press

    Age: 24

    Rhys Hoskins' meteoric 2017 rise culminated in a jaw-dropping first taste of major league action. In 50 games with the Philadelphia Phillies, he put up a 1.014 OPS and hit 18 homers.

    Like Bird, Hoskins' swing is made for putting balls on the other side of the fence. The 31.0 ground-ball, 49.2 pull and 46.0 hard-hit percentages he put up last year all scream, "Slugger!"

    And where most sluggers have exploitable holes, it says a lot about Hoskins that he only struck out nine more times (46) than he walked (37). 

    Likewise, it says a lot about his eye for the strike zone that his walk rate has gotten better every time he's moved up a rung in his professional career:

    • Low-A, 2014: 7.7 BB%
    • Single-A, 2015: 9.0 BB%
    • High-A, 2015: 10.5 BB%
    • Double-A, 2016: 12.1 BB%
    • Triple-A, 2017: 13.5 BB%
    • MLB, 2017: 17.2 BB%

    Amazingly, it gets worse for opposing pitchers. Hoskins plays his home games at Citizens Bank Park, which is the third-smallest (per Business Insider) yard in Major League Baseball.

    Thus, the forecast for his first full major league season: dingers, dingers and more dingers.

Matt Chapman, 3B, Oakland Athletics

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    Tom Mihalek/Associated Press

    Age: 24

    Matt Chapman hasn't been around long, yet he might already be the best-kept secret in Major League Baseball.

    He never occupied prime real estate in prospect lists before debuting with the Oakland Athletics last June 15. In retrospect, that's baffling to at least one extent: He's one of the sport's most talented defenders.

    Chapman made highlight-reel play after highlight-reel play (see here, here and here) in his 84 games with the A's, using quick feet, slick hands and rocket arm strength to get them done. By the end, he'd tallied more defensive runs saved (19) and a higher ultimate zone rating (9.2) than any American League third baseman.

    He wasn't quite as refined on offense. However, he did hit his first two homers off Corey Kluber and finished with 14 long balls to go with a .785 OPS. He has the air-ball swing (33.5 ground-ball percentage) and the patience (9.8 walk rate) to keep the power coming.

    Oh, and he can run, too. He debuted an average sprint of 28.4 feet per second last year. That was second-fastest among third basemen and notably ahead of Jose Ramirez and Kris Bryant.

    Although baseball isn't lacking for stars at third base, it better make room for one more.

Aaron Nola, SP, Philadelphia Phillies

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    Rich Schultz/Getty Images

    Age: 24

    With the help of Baseball Reference, here's a fun look at two National League pitchers' stats from 2017:

    • Pitcher 1: 27 GS, 175.0 IP, 2.31 ERA, 4.6 WAR
    • Pitcher 2: 27 GS, 168.0 IP, 3.54 ERA, 4.5 WAR

    The first set of numbers is from a left-hander with three Cy Young Awards and an MVP—a guy known as Clayton Kershaw. The second set, which features a WAR total that's just 0.1 lower, is Aaron Nola's.

    If nothing else, the comparison ought to give Nola the attention he deserves.

    The Philadelphia Phillies took him seventh in the 2014 draft and put him in the major leagues barely more than a year later. He's seldom looked like anything other than a capable major league pitcher since then and was never better than in 2017.

    Nola maintained command (see his 2.6 BB/9) of four pitches, each of which was a weapon. He increased the velocity of his four-seamer/sinker combination to 92.0 mph last year and continued to flash a bendy curveball and a late-fading changeup. With these, he whiffed 9.9 batters per nine innings and limited hitters to an 85.6 mph average exit velocity.

    All Nola has to do in 2018 is stay healthy and improve his performance against the times-through-the-order penalty, and he'll claim his rightful spot among the Senior Circuit's best pitchers.

Willson Contreras, C, Chicago Cubs

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    Jonathan Daniel/Getty Images

    Age: 25

    The Chicago Cubs' collection of stars is the Kris Bryant and Anthony Rizzo show, featuring everyone else.

    Willson Contreras can change that.

    If he's proved anything in his two MLB seasons, it's that he can hit a lot better than catchers are supposed to. In 193 games, he owns a .278/.356/.494 slash line and has slugged 33 home runs.

    Contreras' bat was functioning better than ever the last time anyone saw him. He finished 2017 with a .972 OPS and 16 homers over his final 57 games. He was running into hard contact more frequently. He kept it up in the postseason by blasting two more homers, including one that traveled 491 feet.

    Simply on the strength of his bat, Contreras can climb higher in the sparse ranks of MLB's star catchers. But not to be overlooked is his defense, which also has potential.

    Although he threw out only 27 percent of attempted base stealers last year, the 37 caught-stealing percentage he posted the season before is more reflective of his arm strength. His framing is another thing that slumped in 2017 but which showed promise in 2016.

    This is a guy who just needs to put all his talents together. There's no reason he can't do so in 2018.   

Byron Buxton, CF, Minnesota Twins

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    Brace Hemmelgarn/Getty Images

    Age: 24

    The last question Byron Buxton needs to answer is whether he can be a consistent hitter.

    He slashed .303/.380/.505 in six minor league seasons but has been an extraordinarily up-and-down batter in parts of three major league seasons with the Twins.

    Buxton has struggled to find comfort with his swing mechanics. That may have changed for good last summer when he ditched a leg kick in favor of a less exaggerated timing device.

    "With the leg kick I was more fly-ball oriented. It didn't give me a chance to get on base," he said last June, per Jake DePue of 1500 ESPN. "Now putting it on the ground I at least have the chance of beating it out or them rushing the throw and making an error."

    Lo and behold, Buxton kept his strikeouts in check and made hard contact more frequently. This translated to a .314/.359/.553 slash line over his final 62 games.

    Any more of that, and Buxton will offer exactly zero nits to pick. After all, he's already a blazing-fast runner who might be the best defensive outfielder in baseball. The Gold Glove he won for his work in center field last year won't be his last.

Alex Bregman, 3B, Houston Astros

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    David J. Phillip/Associated Press

    Age: 23

    The Houston Astros selected Alex Bregman with the No. 2 pick in the 2015 draft and promoted him to the majors the following July.

    That backfired initially, as he collected just two hits in his first 42 trips to the plate. Ever since then, though, he's been a .291/.353/.498 hitter with 27 homers and 19 stolen bases in 196 games.

    Bregman's athletic talents are merely part of what makes him tick. More interesting is how, like a velociraptor, you can see him working things out mentally. He's getting better about laying off junk outside the strike zone and, not so coincidentally, putting the ball in play.

    "You're talking about a 23-year-old kid who plays like a 30-year-old veteran," Jose Altuve, the reigning American League MVP, said of Bregman last October, per Jorge L. Ortiz of USA Today.

    Bregman exited the 2017 regular season on fire, posting a .903 OPS and hitting 11 homers in the second half. He was less consistent in the postseason, but his bat tended to be most visible in clutch situations.

    The defensive metrics mostly confirm Bregman is no Matt Chapman at third base. But he has a good excuse in that he's a natural shortstop who's relatively new to the position. With more experience should come more stability.

    That will solidify him as one of baseball's best infielders.

Christian Yelich, OF, Milwaukee Brewers

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    Brett Davis/Associated Press

    Age: 26

    Another year, another case for Christian Yelich as one of MLB's rising young stars.

    Admittedly, his age puts him closer to being middle-aged by baseball standards. But he only turned 26 last December. And despite being a veteran of five major league seasons, he's not finished tapping into his potential.

    There's already plenty to like about Yelich, ranging from the hitting talents that have built a .290 career average to his solid speed and surprisingly potent power. He doesn't look like a slugger, but his average exit velocity of 95.4 mph on fly balls and line drives is up there among the heavyweights.

    If anything, only one thing was holding Yelich back in the past. Here's a hint:

    • Home: .278/.363/.396 with 18 HR
    • Away: .301/.374/.465 with 41 HR

    Yelich put up those home numbers in 318 games at Marlins Park. Now with the Milwaukee Brewers, he calls Miller Park his new home. It's much more of a hitter-friendly environment and is a place where he can cash in on his preference for balls in the air to left-center field. Those usually didn't clear the fence at Marlins Park.

    Thus, Yelich only needs to be himself to go from good to great in 2018.

                

    Stats courtesy of Baseball Reference, FanGraphs, Brooks Baseball, Baseball Savant and Baseball Prospectus.