Marlins strikeout machine Elier Morillo describes player development journey

After being considered behind the times compared to other major league organizations, the Miami Marlins have invested heavily in player development in recent years. That includes opening a new academy in the Dominican Republic to serve their international signings. They are just beginning to see results  in players like 20-year-old left-handed pitcher Elier Morillo.

Morillo, who signed out of the DR back in 2023 for $100k, idolized Clayton Kershaw growing up because of how he played the game, but later on, he began to watch a lot of Cristopher Sánchez, trying to emulate the Phillies starting pitcher. He was expected to sign with the Baltimore Orioles initially before some talks with the agency of his training academy led him to the Marlins instead.

Morillo spent his first three professional years down in the Dominican. He pitched in 2023 and 2025, but missed all of 2024 rehabbing from Tommy John surgery.

Wakeup time is at 7:00 a.m. at the Marlins' academy, Morillo explains, and depending what time of the year it is, their schedule is different. Usually, when games aren't going on, they go to training soon after waking up, they go through defensive drills and after they go to the gym. They wrap their day up with English class at around 4:00 pm, they wrap up their day.

"It helped me be a better person, better professional and a better player," Morillo told Fish On First in Spanish. "I went into the academy with little experience compared to what I walked out with. I walked out of there as a new person with tons of experience."

As is the case for many others who were not born in the United States, transitioning to stateside life was "a bit tough" for Morillo. He was initially not a fan of the food available to him and at times would skip meals because he could not find something he liked.

During his most recent stint in the Dominican Summer League, Morillo posted a 3.23 ERA, 2.96 FIP, 15.85 K/9 and 4.70 BB/9 in 30 ⅔ innings pitched in 2025.

Going into 2026, Morillo's goal was simple: Have a strong spring training and try to begin at the highest level possible.

"When I saw that the rosters were posted, I saw some players who were a bit down and some excited," Morillo said. "When I saw the Jupiter roster and saw that I wasn't there, I wasn't fazed by it and told myself that we are going to continue to work hard in extended spring training and when the FCL season starts, to have very little outings so I can get to Low-A. After throwing a bullpen in back-to-back days, I was getting out of the gym and I ran into our pitching coordinator and he tells me that I have been promoted to Jupiter."

In 13 appearances (one start) this season for Morillo, he has a 4.30 ERA and 4.20 FIP. Most notably, he has struck out 42.2% of total batters faced, the highest rate in the entire Marlins organization (min. 20 IP). He wants to reach 100 strikeouts and is currently at 57.

One of the main issues for Morillo have been the walks, which is something he admits he needs to improve on.

Morillo has a four-pitch mix: four-seam fastball (63.7%), sweeper (20.3%), changeup (9.2%) and recently added gyro slider (6.8%).

"When there is a left-handed hitter, I know he has no chance because the pitching coach will signal three straight fastballs and I will throw them with confidence, if he hits it or not," Morillo said. "I am also very confident in my defense, but I like to get outs on my own, striking guys out."

Morillo says that his fastball has plenty of ride. It also averages 93.8 mph and in his most recent appearance on Thursday, it topped out at 96.0 mph. His best pitch is his sweeper, which happens to be his second-most-used pitch behind his fastball. It's got a 109 plus stuff and generates a 42.9% whiff rate. He said that the sweeper is a pitch that he has a lot of confidence in, where he can throw it behind the count to get back in at-bats.

Morillo uses his changeup against right-handed hitters. Finally, the gyro slider, a new addition to his arsenal, has graded out well so far, with a 102 stuff plus rating. It averages 83.1 mph. Morillo who admitted the pitch isn't where it should be yet, has allowed a 75% hard-hit rate when using it.

"They told me that for me to be a starter with a good arsenal, I needed to add a pitch that I can play off between the sweeper and fastball," Morillo said. "I can throw the gyro at about 87-88 mph. Little by little, I am getting the hang of it. I don't have a lot of confidence in it right now because I don't dominate with that pitch. I have allowed hits with it because I leave it hanging in the zone, but little by little I am going to begin getting the hang of that pitch."

Morillo is part of a larger experiment. The Marlins under president of baseball operations Peter Bendix use "pitch design" sessions instead of bullpen session and call pitches from the dugout during games. These processes have been implemented from the Dominican Republic up through the majors.

"The first time I saw the pitch design was 2024 in the Dominican Republic before I underwent my surgery," Morillo said. "I personally thought it was a good idea because you have the same system in a bullpen as in a game. What you do in the bullpen, you take to the game. You don't throw the pitch design with the same intensity, but you try to locate your pitches better, work on a specific pitch better, see the weakness of an opposing hitter and find the strike zone more."

Morillo described calling pitches from the dugout as a good transition because of his relationship with pitching coach in the DSL. His numbers in 2025 back up what the Marlins are trying to do as well.

Although his potential call-up is still years away, it is a thought that crosses Morillo's mind, calling it "the best news that I can receive."

"It's a dream I've had since I was a kid," Morillo said. "Right now, what I hope is that I can stay healthy so I can continue to do my job on the field and just have fun."

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