This story was excerpted from Sonja Chen's Dodgers Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.
It was always going to be difficult for Roki Sasaki to live up to the sky-high expectations that followed him from Nippon Professional Baseball to the Major Leagues. Indeed, he has looked every bit the work in progress the Dodgers said he was when they signed him this past offseason.
Sasaki entered the season as MLB Pipeline's No. 1 overall prospect, an indication of how those around the game viewed his tools, upside and potential big league impact. Through eight starts, the 23-year-old right-hander has gone 1-1 with a 4.72 ERA with 24 strikeouts and 22 walks in 34 1/3 innings.
There have been some encouraging moments, but Sasaki's growing pains have stood out against the backdrop of a Dodgers team that has ambitions of defending its World Series title. His latest start was the worst of his young Major League career, as he allowed a season-high five runs across four innings vs. the D-backs on Friday night at Chase Field.
The day after, manager Dave Roberts made it clear that the Dodgers intend to let Sasaki work things out at the big league level.
"There's nothing more impactful than going through a particular experience," Roberts said. "He's going through some struggles right now. Major League hitters tell you what adjustments you need to make. Coaches can tell you things. He can think some things. But ultimately, you can make adjustments, and he will make adjustments, given how the hitters respond. I think you learn that by doing that here."
In no uncertain terms:
"I don't think that a Minor League stint is in any of our minds right now," Roberts said. "But I do think that this learning up here is very, very valuable."
One of the biggest lessons learned has been about Sasaki's arsenal. His splitter can be devastating. His slider has been somewhat of a pleasant surprise. But he needs to have his four-seamer in good shape to make the whole mix work, and it just has not been there.
Here are some takeaways from what we've seen from Sasaki's fastball:
The velo
The homework assignment that Sasaki gave teams when he was posted this past offseason is more of a long-term project in practice. As a refresher, he asked clubs to identify why his velocity dipped in 2024 and to present a plan to ensure that the decline would not continue.
Sasaki's fastball has averaged 96 mph, good for 80th percentile among qualified Major Leaguers, according to Statcast, but it's not the triple-digit heat he was slinging in his NPB days.
"Just really still in this process of finding out what the root cause [is], working with my coaches, talking to people about this," Sasaki said Friday through interpreter Will Ireton. "I'm not quite exactly sure and can't really state exactly the single reason."
The swing-and-miss
Without as much velocity and life on the fastball, it becomes more hittable. When opponents are swinging at Sasaki's fastball, they're making contact. His overall 20.4 percent whiff rate ranks in the 18th percentile, and hitters are only missing on 10.1 percent of their swings against the four-seamer.
A big part of the reason why Sasaki initially began throwing his slider more against big league hitters is because he realized they were hitting his fastball hard. That was a positive development in the sense of him trusting his entire arsenal, but the underlying problem remains.
But as Roberts sees it, it all boils down to …
The command
Sasaki has said he's not dialing back his velocity for better command, which has improved from his first handful of starts.
But since he's not throwing as hard as he's accustomed to, locating his fastball has become even more important. Sasaki needs to consistently establish his four-seamer in the zone in order to make his splitter and slider competitive pitches.
"When you’re throwing mid-90s, 94 [mph], then you got to really command the baseball. So that’s what we’re going to work on as a group," Roberts said. "Roki understands that. And this is still his first season here, so there has to be some grace, as he’s kind of learning this league and kind of getting his footing.”