Amed Rosario was once a top prospect in the New York Mets organization, ranked as high as No. 3 in all of baseball prior to 2017 by FanGraphs, and No. 2 by MLB Pipeline at the time of his debut.
While he sported a quiet bat through much of his minor-league career, Rosario’s physical maturity exploded in the year prior to getting his call with the Mets, resulting in pure domination of Double-A and Triple-A pitchers.
He finally began to grow into his 6-foot-2 frame and the promising, projectable power he showed as a pre-draft prospect finally began to poke its head out. Slashing .328/.367/.466 with seven home runs in 94 Triple-A games prior to his call-up, it seemed like everything was on track for Rosario to live up to the hype and be a building block at shortstop for the Mets, much like Cleveland had in Francisco Lindor.
Then he just ... didn’t.
Unlike Lindor, his rookie campaign was completely unremarkable. After hitting well in the upper minors, he met a brick wall against major-league pitching, slashing .248/.271/.394 with just a 1.8% walk rate and a 28.8% strikeout rate during his rookie campaign. He homered four times in 170 plate appearances, which outpaces the 113.3 home runs per plate appearance he had in the minors, but that doesn’t matter a whole lot if you’re only getting on base 27% of the time.
Those numbers improved, of course, or else he would not have lasted long and would probably have been dumped long before he was sent to Cleveland. But they have never met the sky-high expectations he was given after signing out of the Dominican Republic in 2012. In his four years with the Mets, Rosario holds a .268/.302/.403 slash and 32 home runs (48.9 PA/HR), with a still-too-low 4.3% walk rate and 20.8% strikeout rate.
What happened to the five-tool potential he had as a prospect, and more importantly for the optimistic Cleveland fan, how can he get back there?
In their first assessment post-call-up, Baseball Prospectus had nothing but glowing terms to describe Rosario, and for good reason. He received the aforementioned designation as a “five-tool prospect” and had a shot to be “one of the best shortstops in the game.” They noted that a slide to third base was considered early in his career as a prospect, but he eventually stuck at the much more valuable shortstop position where he was expected to be a Gold Glove contender and could remain for a decade.
Four years later, he was on the verge of being knocked off shortstop by Andrés Giménez — who also came over in the Lindor deal — and while effective at the position, he was far from a Gold Glove-caliber cornerstone. Cleveland has also indicated that he will help at multiple positions, which is code for “not a shortstop.”
In another bit of accidental prophecy, Baseball Prospectus also mentioned his overaggressiveness at the plate and tendency to chase balls out of the zone. It was mostly a footnote, however, because Rosario had such great bat control and speed through the zone that it shouldn’t matter.
Unfortunately, it has.
Since 2017, Rosario has the 14th-highest outside swing rate at 40.2% (for context, that’s a full 34% higher than the best in that time, Logan Forsythe). That alone isn’t enough to prevent someone from being a decent offensive player — others in the 40% to 50% range in that span include Tim Anderson, Javier Báez, Salvador Perez, and Adam Jones — but it certainly isn’t a recipe for success. And if you are going to succeed chasing pitches that often, it’s usually because you swing at everything, not just chasing balls out of the zone as Baseball Prospectus feared.
That’s not exactly the case for Rosario. Whereas someone like Tim Anderson gets by as a free swinger at just about everything and makes enough good contact to be an excellent offensive threat, Rosario doesn’t swing enough inside the zone. And when he does make contact, it’s normally pretty weak. His inside swing rate over his career is 69.7% — middle of the road since 2017, but not nearly where it should be to work with his overall swing profile.
There is some hope, though. Rosario’s plate discipline was seemingly improving year-over-year, leading into a 2019 campaign in which he finished with a .287/.323/.432 slash, career-high 15 home runs, and a dead-average 100 wRC+. He was chasing less than ever at 38.1% and swinging at pitches in zone 71.8% of the time. His swinging-strike rate also came down from 18.1% in his rookie campaign to 12.8% in 2018, and finally 11.6% in his mini-renaissance.
Then 2020 happened. A virus, a delayed season, the return of the McRib — just a boatload of new distractions. Something knocked his progress off track, and he was right back to square one in the pandemic-shortened season with Giménez breathing down his neck.
His pitch recognition seemingly tanked again; while his overall contact rate (77.8%) and swing rate (51.5%) were virtually identical to 2019, he was watching too many pitches go in the zone for strikes again, where his swing rate dropped 5.9% from its 2019 peak.
So, what changed, besides the horror of the McRib? Changeups.
I don’t want to get too big for my analytical britches here and pretend like I’ve solved the puzzle of fixing Amed Rosario, but he saw a huge jump in changeups from the years prior and it seems to have an uneven impact on his performance last year.
From 2017 to 2019, Rosario saw changeups 8.3% of the time. In 2020? He saw them 14.9% of the time — the 43rd most among 223 batters with 140 or more plate appearances.
It’s possible that there is a clear hole in Rosario’s game and other teams saw it (and, to be fair, if they hadn’t before they probably have now). But more than likely, in such an abbreviated season, Rosario was a victim of facing a few extremely changeup-happy teams frequently, maybe a few pitchers he just didn’t see as well as others.
Playing in the National League East, Rosario’s Mets played the Miami Marlins in a sixth of their games. Those Marlins, after suffering the league’s first (and arguably worst) COVID-19 outbreak of the season, were a surprise playoff team thanks to
luck, so much luck, oh my god how did they finished with a -41 run differential and still two games above .500 what on Earth is this a surprising pitching staff. In particular, they threw a lot of changeups — 13.5%, the second-most among NL teams behind only the Giants. Pablo López and rookie sensation Sixto Sanchez threw enough of them to be ranked eighth and 14th among NL pitchers at least 30 innings pitched, respectively. Another rookie, Daniel Castano, threw changeups 24% of the time.
The result, for an overly aggressive Rosario, was a rough outing in a bunch of his games. Whenever he faced a Marlins team that threw at least one changeup, he finished with two hits in 19 plate appearances. Expand that to any team that threw him at least one changeup (23 total games) and he finished with 13 hits in 85 plate appearances. In games where he faced changeups at least a third of the time (seven total games), he had just one hit in 23 plate appearances.
Rosario is not particularly swing happy against changeups, either. But he makes especially weak contact against them. Last season he made hard contact on changeups just 8% of the time, compared to his overall average 33% hard-hit rate.
The hope of all this, if you’re a fan of the Cleveland professional club of baseball players, is that he just was not comfortable playing against a small subset of changeup hurlers that he had to face a lot of in 2020, and in a short season that made him look like a well-below-average hitter. Hope that the spike in offspeed pitches came because he faced the Marlins and other offspeed-heavy teams — and by sheer coincidence — he did not do well against them last season. Steamer would buy into this at least a little bit, putting him at a .281/.322/.432 slash with 14 home runs, a 5.3% walk rate, and still-below-average-but-better-than-last-year 93 wRC+.
Regardless of if the sudden influx of changeups were the problem or there’s an overall need for better pitch recognition, it gives a starting point for how to get him closer to his breakout two years ago. Hoping that opposing pitchers throw him fewer changeups is certainly not enough to reinvigorate his bat, but it could explain something that Cleveland saw in him worth bringing over in the Lindor deal.
Best case scenario, Rosario could be someone in deep need of a change of scenery. The Mets organization was a mess for a while, and maybe he just needed out and into the clear skies of Northeast Ohio and Cleveland gets one hell of a utility guy. We’ll find out in a couple months.