Meet Padres Fireman Adrian Morejón, MLB’s Most Underrated Reliever

The Padres’ most valuable reliever isn’t who you think it is.

Mason Miller is widely considered the best closer in baseball and has authored historic stretches of dominance since arriving in San Diego at the trade deadline last season. But even he recognizes he may not be the most important bullpen piece his team has. While he may not touch 104 mph like Miller and he may not have the same name recognition, Adrian Morejón is every bit as important. And possibly more so.

On Wednesday night in Game 2 of his team’s NL wild-card series against the Cubs, Morejón made a slow jog to the mound to open the top of the seventh inning as his team nursed a 4–1 lead. Built like a tank, the 5'11", 224-pound lefty doesn’t have Miller’s towering presence but his stuff is just as devastating.

Using just 14 pitches—11 of which came in at 99 mph or higher—he dispatched Carson Kelly, Dansby Swanson and soon-to-be NL MVP Pete Crow-Armstrong. He was so efficient that he returned for the eighth, where he induced a flyout from Alex Bregman and allowed a single to pinch-hitter Tyrone Taylor before getting Seiya Suzuki to ground back to him for a 1-6-3 double play. He made handling baseball’s best regular-season offense look easy and set the table for Miller to close the game in the ninth.

“He’s the most valuable reliever on our team and, I would argue, in baseball too,” Miller said. “The ability to get swing-and-miss, the ability to limit damage, the ability to be really efficient—I think that’s the separator for him. There are so many guys that have really good stuff in this game, but the reason he’s able to throw so often and so many innings is obviously what he does to prepare for the games, but also his ability to go after guys, strike guys out if he needs to.”

More than a setup man

Morejón established himself as a key part of the Padres’ bullpen in 2024 before breaking out in ‘25. He went 13–6 with a 2.08 ERA, a 0.90 WHIP and 70 strikeouts against 17 walks in 73 ⅔ innings. Those 13 wins were the most by a reliever since Rogers McDowell had 14 for the Mets in 1986.

Following that huge season, Morejón was just as good, if not better, in 2026. He finished the regular season 9–3 with a 2.83 ERA, a 1.08 WHIP and 107 strikeouts against 28 walks in 86 innings. Even those numbers undersell how dominant Morejón was this year. His full-season numbers were inflated by two early blowups, but the 27-year-old locked in after a shaky start. He allowed 13 earned runs by May 10 and surrendered 14 the rest of the way. After that date, he went 7–2 with a 1.93 ERA and 81 strikeouts in 65 ⅓ innings. He finished the season ranked fourth among MLB relievers in fWAR (2.8).

Morejón ranked third in relief innings pitched this year behind AJ Blubaugh (96) and Aaron Ashby (87). He also had 25 outings of more than one inning, which is roughly one-third of his appearances.

That combination of dominance and durability gives Padres manager Craig Stammen a weapon few teams have at the back of their bullpen.

“He’s a dynamic reliever. He can pitch multiple innings or be dominant for one inning,” Stammen said. When asked whether he could picture San Diego’s bullpen without Morejón, Stammen was blunt: “Cannot.”

A decade in the making

Morejón’s journey from young phenom to bullpen dominance was not a straight line. He is the longest-tenured player in the Padres organization after signing with the franchise more than a decade ago.

At a young age, Morejón looked like one of the best pitching prospects in the world. A native of Havana, he played on several Cuban youth national teams. He pitched for his country at the 2011 12U Baseball World Championship and was named MVP of the 2014 15U Baseball World Cup as Cuba beat the United States 6–3 in the championship. Morejón earned the win in the title game, while Reds All-Star Hunter Greene took the loss.

In October 2015, Morejón left Cuba. After spending two weeks in Ecuador, he spent a day in Haiti before reaching the Dominican Republic, where he set up residence and began training. In July 2016, the 17-year-old signed with the Padres for $11 million. He has never known another franchise.

After years of minor league success, Morejón, then a starter, reached the big leagues on July 21, 2019, at 20 years old. He made five appearances (two starts) and posted a 10.13 ERA. He pitched in nine games during the COVID-19-shortened 2020 campaign and struggled his way to a 2–2 record with a 4.66 ERA and 1.24 WHIP in 19 1/3 innings. His development was interrupted early in the 2021 season, when an injury to his left UCL led to Tommy John surgery that cost him all but 4 2/3 innings on the season.

He returned in 2022 as a reliever but, over the next two seasons, struggled to carve out a consistent role. He made 34 appearances over those seasons combined and went 5–1 with a 4.81 ERA in 43 innings. During that time he suffered shoulder inflammation, and a sprained elbow cost him 60 games.

Things finally came together in 2024. Nearly a decade after he carved up U.S. hitters to help Cuba win a youth world championship, Morejón finally began dominating professional hitters the same way.

San Diego Padres relief pitcher Adrian Morejon and catcher Freddy Fermin. — Adrian Morejón’s versatility out of the bullpen is a major weapon for the Padres. | IMAGN IMAGES via Reuters Connect

The pitch that changed everything

So what turned Morejón from a talented but injury-prone lefty into one of baseball’s best pitchers? He added a sinker to his arsenal before the 2024 season and everything clicked.

In 2023, Morejón threw his four-seam fastball 57.8% of the time and backed it up with a slider (19.3%), curveball (12.4%) and changeup (8.7). In 2024, he completely reworked his pitch mix.

Morejón deployed a sinker 36.2% of the time in 2024 and it averaged 97.4 mph. Opposing hitters managed a .317 xwOBA against it, but how the pitch played with the rest of his stuff is what changed everything. He upped his slider usage (29.8%) and the pitch flourished, generating an xwOBA of .239. His four-seamer usage fell to 23.2% and has remained below its 2023 level ever since.

After throwing his sinker 61.8% of the time in 2025, Morejón diversified his offerings this season, opting for more changeup usage. The sinker remained his primary offering as he used it 47.6% of the time. The pitch averaged 99.5 mph and featured 16 inches of arm-side tail. Opponents only managed an xwOBA of .300 against it. The changeup was his second most frequent pitch (23.1%). It came in at 92.1 mph, averaged 10.7 inches of arm-side movement and hitters posted a .127 xwOBA against it. Morejón used the pitch almost exclusively against right-handers, with 291 of the 301 he threw coming against them. The pitch had an absurd 56% whiff rate this season. The slider (15.2%) and four-seamer (14.2%) were mixed in as well, but the sinker-changeup combination is his bread and butter.

The move to a sinker changed Morejón’s career. The development of his changeup made him a complete pitcher in 2026.

Now comes the hard part

Morejón’s development is a massive success story for the Padres, but an end date appears to be coming. Despite their status as a playoff contender, San Diego received plenty of interest in him at the trade deadline with the lefty approaching free agency.

“You could tell from the phone calls that came in all week and the last couple weeks,” Padres president of baseball operations A.J. Preller said after the deadline had passed. “The industry appreciates and realizes what kind of talent [Morejon] is and the impact he’s had for our team and our organization.”

Preller opted to retain him, citing both his performance and decade-long connection to the organization.

“He’s one of the best relievers in the league. And the respect that he has in the clubhouse—he’s a guy that was signed by the Padres in 2016, we feel like he’s grown up in the organization,” Preller said.

Given how he’s pitched the last three seasons, Morejón is set to cash in this offseason. At 27, with elite stuff and the ability to handle a heavy workload, he will be one of the most coveted pitchers on the market this winter.

Morejón has made it clear where he wants to be.

“Everybody knows that I want to stay here. Even with free agency coming, they know I want to stay,” he said. “This is the organization I’ve been a part of for more than 10 years. I’ve sacrificed a lot. I’m proud to be a member of the Padres. Hopefully that will continue.”

Many of his teammates feel the same way and haven’t been shy about it.

During a raucous clubhouse celebration after the Padres clinched a postseason berth, Fernando Tatis Jr., who was standing with Morejón, interrupted an interview with Preller and said, “Pay him! Pay him,” before adding, “He can’t leave me. I need him!”

Soon the Padres will find out what other teams are willing to pay for the man the sport’s best closer called baseball’s most valuable reliever.

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