Rarely does a young pitcher draw global attention so quickly, but Roki Sasaki has done exactly that. From his elite career in Japan’s NPB to his high-profile arrival with the Los Angeles Dodgers, Sasaki’s journey is filled with promise, adjustment, and postseason intrigue. In this post, we’ll trace Sasaki’s background, his 2025 season with the Dodgers, how the team uses him now, and what fans should expect going forward.
Origins & Japanese Stardom
A Rising Star from Iwate Prefecture
Roki Sasaki was born on November 3, 2001, in Rikuzentakata in Iwate Prefecture, Japan. His childhood was marked by tragedy: during the 2011 Tōhoku earthquake and tsunami, his home was destroyed and he lost his father and grandparents. Through hardship, baseball became a solace.
In high school, Sasaki already turned heads. He unleashed a fastball clocked at 163 km/h (about 101.3 mph), breaking the Japanese high school speed record previously held by Shohei Ohtani. Because of that, he earned the nickname “the Monster of the Reiwa Era.”
NPB Breakout & Perfect Game
After being drafted first overall in 2019 by the Chiba Lotte Marines, Sasaki’s development was carefully managed. The team held him out of competition in 2020, then made his debut in 2021.
His most iconic moment in Japan came on April 10, 2022, when he threw a perfect game against the Orix Buffaloes. In that outing, Sasaki struck out 19 batters, tied the NPB record, and set a new standard for consecutive strikeouts (13 in a row). That game etched him into Japanese baseball lore.
Over his NPB tenure, Sasaki compiled excellent stats — in his final seasons, for example, he posted a 2.35 ERA with 129 strikeouts in 111 innings.
Because of his elite pedigree, many MLB scouts and analysts believed he was ready to make the jump.
Arrival in MLB — Signing with the Dodgers
Dodgers Acquire Sasaki
On January 22, 2025, the Dodgers announced they had signed Sasaki. The deal included a $6.5 million signing bonus, and because he was under 25, the contract followed minor league posting rules. He joined a Dodgers roster already boasting Japanese stars like Shohei Ohtani and Yoshinobu Yamamoto.
Almost immediately, media labeled him MLB’s “#1 prospect entering 2025” among international signees.
Debut & Early Struggles
Sasaki made the Dodgers’ Opening Day roster and debuted on March 19, 2025, in the MLB Tokyo Series against the Cubs. In his first outing, he allowed one run on one hit, walked five, and struck out three. His first MLB strikeout was Seiya Suzuki.
He earned his first major league win on May 3 versus the Braves. But his season was derailed by injuries — he was placed on the injured list with a right shoulder impingement on May 13 and later moved to the 60-day IL.
After rehab stints in Triple-A, Sasaki returned in late September, but now in a different role: as a relief pitcher rather than a starter.
By season’s end, his MLB stats read:
- Win–loss: 1–1
- ERA: 4.46
- Strikeouts: 28
- Walks: 22
His shift to the bullpen showed Dodgers’ flexibility in using a talented arm in high-leverage innings.
Sasaki in the Postseason — Closer Role & Big Moments
Though Sasaki started the year trying to find his footing, his postseason usage has become a talking point.
NLDS Heroics
In the 2025 NLDS versus the Phillies, Sasaki made a splash in his playoff debut. He threw three perfect innings, helped secure two saves, and was part of the clinching effort in Game 4. This performance led some to call him the team’s new go-to closer in October.
His control, velocity, and composure in those innings stood out—even under playoff pressure.
NLCS & Challenges
Entering the NLCS against the Brewers, Sasaki’s role continued to expand, and Dodgers manager Dave Roberts publicly signaled he’d rely on Sasaki in relief situations.
But Game 1 presented a rough outing: Sasaki allowed one run on one hit with two walks in just two-thirds of an inning. He was removed before converting the save.
Still, his earlier postseason work had already left a mark. Some observers likened him to a reliever of Rivera-esque poise.
Pitching Style, Arsenal & Future Outlook
Arsenal & Mechanics
Sasaki’s fastball generally sits in the 96–100 mph range, with occasional spikes over 100. But what draws the most attention is his splitter — a pitch that produces low spin and late movement. Early in spring training, his splitter recorded an 83% whiff rate (10 swings and misses in 12 swings).
Scouts note that while his velocity is major-league ready, his secondary offerings and command will dictate long-term success.
Strengths & Risks
Strengths:
- High ceiling with elite velocity
- Splitter that keeps hitters off balance
- Postseason composure when called upon
- Youth — still only in his early 20s in MLB
Risks / Challenges:
- Injuries — the shoulder issues in 2025 underscore fragility concerns
- Control inconsistency — 22 walks in limited appearances is notable
- Adapting to MLB’s level of hitters — NPB dominance doesn’t always translate seamlessly
- Role uncertainty — starter vs reliever deployment remains fluid
The Dodgers, recognizing both the upside and caution, appear to be leaning on Sasaki more in bullpen duty during October, preserving his arm and maximizing his impact.
What “Sasaki Dodgers” Means for Fans & Baseball
For U.S. fans, the name “Sasaki Dodgers” signals a high-stakes gamble by Los Angeles: importing Japanese pitching royalty and entrusting him with critical playoff innings. It also broadens the international flavor of the Dodgers — a team already featuring Shohei Ohtani and Yamamoto — and positions Sasaki as part of a pitching renaissance in L.A.
For Dodgers Sasaki fans (or fantasy baseball watchers), tracking his usage, innings, and leverage spots will be exciting. His postseason breakout has already turned heads across MLB media.
In short: Sasaki’s presence elevates every Dodgers discussion — from bullpen depth to postseason plans, from rotation composition to young arms’ futures.
Conclusion & What’s Next
Roki Sasaki’s transition from Japanese phenom to MLB playoff weapon has been dramatic, uneven, and full of promise. He’s had to navigate injuries, role changes, and pressure nights, but his postseason flashes have already shown what he might become: a high-leverage arm with electric stuff.
For U.S. fans watching roki sasaki, sasaki dodgers, or dodgers sasaki, here’s what to track going forward:
- His usage in high-leverage postseason innings
- Whether the Dodgers gradually shift him back toward starting roles
- How his command and walk rates evolve
- Whether his splitter continues to be one of MLB’s nastiest secondary pitches
- His health trajectory — avoiding injury is critical
