MLB

These 3 Former MLB Prospects Have Gone From Busts To Busting Out

Jarred Kelenic, MacKenzie Gore and Geraldo Perdomo were running out of time to reach their potential — but no longer.

By Alex Kirshner

Apr. 18, 2023, at 10:29 AM

In 2021, Jarred Kelenic was the No. 4 prospect in baseball, according to MLB Pipeline. That placed him one spot ahead of a fellow Seattle Mariners outfield prospect, Julio Rodriguez, at No. 5. But while Rodriguez would soon become one of the most awe-inspiring young mashers in years — and sign a huge, complicated contract worth several hundred million dollars — Kelenic sputtered. He played in 147 games over the next two years and posted an adjusted OPS of 66. (The league average is 100.) His triple-slash line was .168/.251/.338 in his 588 plate appearances across two seasons. The Mariners demoted him to Triple-A in 2021 and then, upon trying again in the majors, demoted him again in 2022. He came back to the bigs just before the trade deadline and posted a putrid .561 OPS down the stretch. 

That same year, the sport’s No. 6 prospect was MacKenzie Gore, a left-handed pitcher then working in the San Diego Padres’ organization. Gore had been the No. 5 prospect the year prior and remained highly regarded despite some less-than-sparkling minor league stats. Gore was in the Padres’ starting rotation by April of 2022, and though he struck out more than nine batters per nine innings, he also walked nearly five per nine and gave up 0.9 home runs per nine, too. When he went to the injured list with elbow inflammation in late July, his ERA+ was 84. He didn’t pitch another game that season. Nor did he end the year as a Padre: The Washington Nationals acquired the injured Gore in the trade that sent Juan Soto to Southern California. Gore still had value, clearly, but would soon be 24 and had yet to put much together as a major leaguer.

Further down the prospect ranking in 2021, at No. 79, was Geraldo Perdomo. The Arizona Diamondbacks’ up-and-coming shortstop was in his second year as a top-100 prospect and represented hope for a D-backs team that was about to finish last in the National League West for the second straight season. Perdomo appeared in 11 games at the end of 2021 and looked promising, posting a 117 OPS+, but his first full year in the bigs was horrible: a .195/.285/.262 slash line, a 57 OPS+, and 0.63 wins above replacement, according to an average of FanGraphs’ and Baseball Reference’s systems. Perdomo’s defense at shortstop was the only thing that prevented him from providing zero value for Arizona.

Kelenic, Gore and Perdomo had each followed similar paths: Become a top prospect, get to the major leagues and sputter. This year, they all have something else in common: They’re starting to fulfill their onetime promise. Each looks to be staging a 2023 breakout and vindicating the industry’s view of them — just a year or two later than expected. If at first a top prospect doesn’t succeed, then maybe he will a bit later. 

In these early weeks of the season, Kelenic has been arguably baseball’s most fun player to watch. For one thing, he hit a 482-foot home run into the upper reaches of the center field Wrigley Field bleachers: 

It was the second-longest homer of the MLB season to date, just behind a 485-footer off the bat of (who else?) Giancarlo Stanton. And it was representative of Kelenic tearing the cover off the ball with alarming frequency. He homered in four straight games from April 10 through 14. On every conceivable player-tracking metric that points to “hitting the ball really damn hard,” Kelenic is currently a Statcast star. He’s in the top 12 percent of MLB in average and maximum exit velocity, barrel percentage, hard-hit percentage and expected batting average and slugging percentage. Naturally, it has all translated to top-end production: Kelenic is hitting .362/.423/.723 through Sunday, good for a 219 OPS+. 

Kelenic has even been quite a bit more productive than Rodriguez, making it feel less weird that the two were once considered more or less equal prospects. Fortunately for the Mariners, Kelenic-Rodriguez is not a competition. They get to have both of them. And just as Rodriguez played a pretty good center field for the Mariners last year, saving a handful of runs over the course of the season, Kelenic has shown some good things in right field. Consider this web gem from the weekend: 

Across the country, an apparently healthy Gore has gotten it rolling, despite not yet figuring out the biggest thing that plagued him last year. In three starts totaling 15 innings, Gore has walked 6.0 hitters per nine innings but struck out 10.8. He’s sporting a round-numbered ERA of 3.00 and has won both of his decisions. In some subtle ways, he’s been a much different pitcher than he was in 2022. 

Gore’s fastball velocity is basically steady (94.5 mph, down from 94.7), and he’s thrown it with the exact same frequency (on 60.9 percent of his pitches) as last year. But he’s generated velocity upticks of between 1 and 3 miles per hour on his other three pitches: a curveball, slider and changeup. Hitters have swung and missed at 30 percent of his pitches, up from 24 percent, even as he throws pitches in the zone at a rate (49.5 percent) that’s just one-tenth of 1 percent different from last year. When hitters do get bat on ball, they’re beating it into the ground at rates that are unusual for Gore. He typically posted ground ball rates in the mid-40-percent range as a minor leaguer, and 37.6 percent of balls put into play against him last year were grounders. This year, the figure is 51.4 percent. Gore has become both harder to touch and harder to really get a hold of, and it’s all helped him overcome those persistent walk problems. 

As for Perdomo, he wasn’t quite as hyped a prospect as Kelenic or Gore, but he’s been just as exciting to watch out in the desert. One of Perdomo’s great traits as a minor leaguer, after the D-backs signed him as an international free agent from the Dominican Republic in 2016, was his plate discipline. Perdomo has always generated double-digit walk rates, and at several minor league stops he walked more often than he struck out. For him, a 10 percent walk rate in 2022 against a 20.6 percent strikeout rate qualified as quite bad. So far in 2023, though, Perdomo has walked on 15.2 percent of his plate appearances, the 41st-highest rate in MLB. 

He’s also struck out more, going down that way 24.2 percent of the time. But he’ll take that trade, given that he’s been crushing the ball when he gets into it. Perdomo has found power like never before in his professional career. His .240 isolated power rate (the difference between his slugging percentage and batting average, which isolates extra bases) is 60th in the league. It’s been just a few weeks, but for a frame of reference on how powerful Perdomo has been: There have been just 27 seasons since 2000 in which a qualifying shortstop has posted an ISO higher than .240, and four were Alex Rodriguez from 2000-03. Even assuming Perdomo cools off considerably, he could be an ultra-powerful shortstop. Manager Torey Lovullo is bringing Perdomo around with some caution, however. He has mostly hit eighth or ninth in the batting order, and from a place of less pressure he’s offered a .400/.516/.640 line and 213 OPS+, through Sunday. 

The Diamondbacks lost 110 games in 2021 but improved to 74-88 in 2022. This year, FiveThirtyEight’s predictive model sees Arizona hovering around .500, projecting an 80-82 record. The machine gives the D-backs a 32 percent chance to make the playoffs. Perdomo’s continued development is maybe the clearest way Arizona could make a run at its first postseason berth since 2017 or first postseason win since 2011. Similarly, Kelenic sustaining his early breakout would do wonders for the Mariners’ current playoff odds of 36 percent. Gore, by contrast, could be a combination of Pedro Martinez, Greg Maddux and Nolan Ryan for the rest of the season, and the Nationals (projected record: 62-100) would not make the playoffs. But he at least has a chance to make Washington watchable every fifth day. And if Gore can do that, he’ll have gone a long way toward justifying his status as one of the sport’s rising stars.

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