Before he held the keys to the Los Angeles Dodgers’ fortunes and before Major League Baseball was introduced to the monster, Roki Sasaki was lost.
No pitcher inspired more conversation last winter than Sasaki, who brought more promise to the international market than any player since his now-teammate Shohei Ohtani. Then Sasaki all but disappeared from the Dodgers’ plans by midseason, looking like a shell of his former self with an achy shoulder and the most hittable fastball in the sport. Now, as the Dodgers are set to face the Milwaukee Brewers in the National League Championship Series, no pitcher may be as important as the beast that Sasaki has become — a relief ace for a shaky bullpen who has made the most of his second chance at a first impression.
The “Monster of the Reiwa Era,” as the 23-year-old is known in his native Japan, has arrived. Look no further than the three perfect innings he delivered in the series-clinching Game 4 of the National League Division Series against the Philadelphia Phillies. His fastball hummed at triple digits, located precisely where Sasaki wanted to put it. His splitter, a unicorn pitch that tumbles toward the plate, danced. He challenged the best hitters in the sport, who had no answer for him.
Between innings, Sasaki stood in the corner of the dugout, never removing his glove and staring straight ahead, like a predator waiting for more prey to devour.
“One of the great all-time appearances out of the pen that I can remember,” manager Dave Roberts said.
“I mean,” reliever Alex Vesia added, “he goes down in the history books.”
“Since coming back, coming in from the bullpen, he’s honestly one of the best pitchers I’ve ever seen,” said Tyler Glasnow. “His stuff is incredible. He’s locked in around the strike zone. For him to start the season how he did, and then come back now, it’s one of the craziest things I’ve ever seen.”

It took some struggling in the minors and a breakthrough video session, but Roki Sasaki found his groove again. (Bill Streicher / Imagn Images)
This is all still so new. Six weeks ago, Sasaki was floundering on a rehab assignment in Oklahoma City with a fastball that sat in the mid-90s and got pummeled, plus an out-of-whack delivery stemming from years of injuries. His confidence appeared to wane with each blow-up outing.
This is all still so important. Sasaki has now thrown 5 1/3 innings this postseason, with still fewer than 10 innings of relief work in his professional baseball life. In the 15 relief innings Sasaki hasn’t thrown this postseason, the Dodgers’ bullpen has allowed 13 earned runs.
Sasaki is no longer a fantasy. He is no longer irrelevant. Thanks to a late-season reinvention, he is everything.
“It’s real,” Kiké Hernández said. “Here he is. He’s putting himself on the map.”
This has been a revelation. This is also who Sasaki has always been.
As the Dodgers’ vice president of player personnel, Galen Carr logs about as many miles as anyone in the organization on travel to Japan. He has scouted the nation’s top talent, from Ohtani to Yoshinobu Yamamoto to Sasaki. To say he discovered Sasaki is a fallacy; the pitcher was one of the most famous products the country ever produced, emerging from high school with one of the hardest fastballs anyone had ever seen and a hybrid splitter/forkball that was a singular force. He pitched with ferocity and carved a narrative and nickname for himself that was the stuff of legend.
“He was one of the best pitchers in Japan when he was healthy,” Carr said this month. “I mean, he almost threw two perfect games in a row. Who does that?”
Sasaki was starting to see a decline in his fastball velocity even before he was officially posted to MLB clubs in the winter. His shoulder gave him trouble during his final season with the Chiba Lotte Marines. An oblique injury on top of that limited him to 18 starts that year. His lagging velocity sparked enough concern that when Sasaki went through his recruitment process last winter, he asked interested clubs how they would help him get back to the triple digits he’d previously averaged.
The mystery continued into his first season with the Dodgers. Sasaki hit 100 mph twice in his first inning in the big leagues, pitching in a packed Tokyo Dome during what was supposed to be a coronation of the Dodgers’ dominance of the Japanese market. Sasaki didn’t hit 100 mph again as a starter.
Eight starts revealed the cracks that had formed over the years. Sasaki’s velocity was still down, as his fastball averaged 96 mph. That, combined with a flat trajectory, made the pitch one of the most hittable in the sport — his 11.1 percent swing-and-miss rate on the fastball was 10th worst in baseball for any pitcher who threw at least 300 of them. What’s more, Sasaki couldn’t command his fastball or his splitter, leaving an uninspiring slider as a load-bearing pitch in his arsenal. The results were ugly, with a 4.72 ERA in 34 1/3 innings before Sasaki complained that his shoulder was giving him trouble again.
Sasaki essentially disappeared from the forefront of a frustrating Dodgers summer. He did not address the media for months while on the injured list, strengthening his shoulder and adding bulk in hopes of better preparing his frame for the rigors of Major League Baseball. Still, he looked to be the odd man out. The Dodgers’ standout rotation was getting healthy. Roberts repeatedly pointed to Sasaki’s performance, as much as his health, being a factor in his even being considered for the club’s stretch run.
When he started a rehab assignment, the issues persisted. Sasaki’s velocity was still down. He got bombed even against Triple-A hitters. Roberts had to swat away continued questions about Sasaki’s health, and the right-hander drifted further toward the periphery of the Dodgers’ plans.
“I am surprised,” Roberts said on Sept. 5. “Because the talent level is certainly there. The performance, the stuff, hasn’t been there. I think there needs to be a tick up in stuff. And also against Triple-A hitters, you would expect more.”

In Japan, Roki Sasaki nearly pitched two perfect games in a row. It took some time to adjust to the majors, but he figured things out. (Daniel Shirey / Getty Images)
The Dodgers sent Sasaki to Arizona, where they had him break down hours of video with Rob Hill, the organization’s director of pitching. Hill’s fascination with Sasaki started long before the pitcher put on a Dodgers uniform. Hill was intrigued by Sasaki’s unique arsenal and his striking delivery, which featured a high leg kick and crane-like appendages flying everywhere. During that video session, Hill noted some bad habits that crept in as Sasaki dealt with injuries in recent seasons. Sasaki’s arm slot fell out of place, Hill said, because of how he threw his slider. Sasaki’s shoulder injuries forced him to expend more energy to generate the same velocity, putting more strain on his arm while using less power from his legs.
Sasaki applied the corrections. It took time, the Dodgers admit, for Sasaki to open up to outside input. The right-hander has brought his crew of confidants and advisors through every part of his acclimation to the majors. Being receptive to new ideas required trust.
“There’s been moments where he’s like, ‘No, I feel really convicted in this,’” pitching coach Mark Prior said in August when asked how Sasaki was taking feedback. “Obviously, that’s their decision. … I think ultimately we’ll find out once we start facing real hitters in real situations and then you find out really where that openness, where that line is, good and bad.”
“Any new player that you acquire, it takes a little while to build up trust,” Dodgers president of baseball operations Andrew Friedman added. “We didn’t try to push it too early. We knew that he was a guy that was accustomed to doing things a certain way and we were going to embrace that.”
Sasaki threw a bullpen session with the changes in mind, notably bending his back leg at the start of his delivery. That locked everything else into its old place and forced Sasaki to be more athletic and less robotic in his delivery. The velocity jumped. His command improved. This was the Sasaki he knew, the version baseball executives fell in love with.
“Just felt like my fastball velo was back to where it used to be, and the command of the fastball was where I wanted it to be as well,” Sasaki said through interpreter Will Ireton. “So I think that really helps with the off-speed. And because of that, I do really feel confident to be able to attack in zone.”
Circumstances helped bring Sasaki back to the forefront. As he got his stuff back, the Dodgers’ bullpen was crumbling. Overused for much of the season, once-reliable relievers began dropping one after another. So the Dodgers’ brass broached the idea of using Sasaki in relief. He agreed.
It’s been a godsend and unlocked a persona that Sasaki has seemingly embraced.
“The presence on the mound, the conviction to make every pitch, to be in the strike zone with his fastball, he knows how good he is right now,” Carr said. “His split’s as good as I’ve ever seen it right now.”
The monster has been unleashed.
(Top photo: Emilee Chinn / Getty Images)