Making the Mariners' pitch to Rōki Sasaki
The 23-year-old Japanese phenom has a chance to thrive and change the arc of the franchise.
Rōki Sasaki is a baseball player with a lot of talent who is available for not a lot of money. It’s a combination that has the Mariners, on this rare occasion, realistically in the market to acquire an elite MLB-ready free agent.
And maybe the market just got a little more open with the Dodgers signing Blake Snell to a five-year deal? Probably not, but we can delude ourselves. We’re Mariners fans.
A team signing Blake Snell wouldn’t take them out of the Sasaki market but getting knocked out of the Sasaki market might make them sign Blake Snell.
Dare to dream?
Back to Sasaki, the right-handed starter’s future deal will face the same constraints Shohei Ohtani’s did back in 2017—because he’s under the age of 25, he’ll sign as an amateur and his deal will be subject to international signing bonus restrictions.
If he signs after January 15th, as is the assumption the Mariners will have as much bonus money in their pool than anyone, a hefty $7.55 million. That’s a little less than Whit Merrifield received for signing with the Phillies last offseason. Whether it’s all actually available and not already promised—because of the way shady international free agent deals work—is a different story.
Either way, short-term money will not be the deciding factor. What will be? Who knows. Shohei once chose the Angels. The Los Angeles Angels of Anaheim!
The background on Sasaki
First, the player, who are we talking about?
Eric Longehans covered the player and his market in this August piece for FanGraphs. He offers this quality synopsis on the former:
Sasaki has been the LeBron James of Japanese baseball since his junior year, a known generational high school talent who has gone on to deliver on and perhaps exceed expectations at the highest level of Japanese baseball. Sasaki turns 23 in November and his feats of strength are already legendary. He touched 101 in high school and once threw nearly 500 pitches in an eight-day span, including a 12-inning, 194-pitch complete game during which he also hit the game-winning two-run homer. He was the first pick in the 2019 NPB Draft by the Chiba Lotte Marines, had a sub-2.00 ERA in his 2021 rookie season, and then transcended the sport in 2022 when he threw 17 consecutive perfect innings that April.
The 6-foot-2 righty retired 52 consecutive batters (the MLB record is Yusmeiro Petit’s 47) during that stretch. His fastball averaged just shy of 99 mph in 2023 and he touched 103, making him the hardest-throwing pitcher in NPB history. He has one of the planet’s nastier splitters, and his slider quality also leapt in 2022. Sasaki was having an even better 2023 — 85 IP, 39% K%, 5% BB%, 62% GB%, 1.88 ERA, 0.92 FIP — before he was shut down with an oblique tear in July, which cost him most of the rest of the season and was a harbinger of things to come in 2024.
You would probably not be shocked to learn he’s dealt with arm injuries as of late. Read Eric’s full piece for the details.
His health hasn’t been a major topic of conversation because
It hasn’t been that bad yet and
It doesn’t matter because, again, the cost outlay far outweighs the talent (and potential talent), even with some injury concerns
As such, the field is wide open.
The Mariners will make their pitch. And it’s not a bad one.
Here’s what I imagine it will hit, or what I’d hit—appealing to both reason and emotion.
The head: the Mariners are as good at pitching development—and management—as anyone
It’s important to underscore, again, that we do not know what motivates this kid. No idea. It matters for this part and the next passage. We can guess what might matter, and that’s what I’ll do, but this stuff might not register at all.
Still, Sasaki is in a unique predicament. Ohtani is a comp for contractual reasons, yes, but Sasaki’s coming over as only a pitcher. He’s a young pitcher who will look to navigate the chasm between prospect and elite performance at the sport’s highest level.
His star shines brighter than Logan Gilbert out of Stetson or George Kirby out of Elon ever did, but what he needs is something the Mariners are as good at as anyone in the sport.
We’ll get into the quantitative side of this but, first, the more abstract. Here’s Mariners broadcaster Gary Hill Jr. talking to talking to Mike Lefko on Seattle Sports a few weeks ago.
“If you were a pitcher coming over and interested in being a better pitcher, there’s not many teams that can make a better case for the Mariners right now,” Hill said. “When you think about the smartest teams in baseball and when you have conversations with people outside of Seattle and talking about just baseball observers, a lot of the same teams are mentioned when it comes to the smartest teams when it comes to pitching. You hear about Cleveland all the time here, Tampa Bay all the time and the Mariners are now in that conversation given what they’ve done, especially with the rotation and how they’ve developed guys through their system.
You can’t deny it.
If you were a pitcher looking to find their footing in Major League Baseball and perform as well as possible from the jump, it’d be tough to beat the results Seattle can point to.
Since 2022, here’s where the Mariners rank as an organization for starting pitching from guys age 27 and under:
fWAR: 1st
Innings: 3rd
Starts: 4th
ERA: 1st
FIP: 1st
WHIP: 1st
Strikeouts: 2nd
K-BB%: 2nd
What Sasaki needs is what the Mariners do. And this doesn’t happen by accident.
You can look to Baseball America and work they published earlier this offseason ranking each farm system by their pitching using Statcast and the publication’s own internal Stuff+ metric. I’ll give you their methods because you don’t need all the data.
I’ll spoil it right now. According to Baseball America’s ranking of pitching prospect systems, nobody has better young arms than the Mariners.
Here’s how they measured:
Statcast data allows us to look beyond performance and subjective analysis of prospective major leaguers. Pitch-level data allows us to add context to the difference between two pitches at the same velocity that may generate very different results. For example, understanding how a pitch moves to the plate and the traits that impact the ball’s flight allow us to more properly assess the quality of that pitch. In turn, this allows us to get a more accurate understanding of how that pitch will translate against major league hitting.
Examined below is a combination of pitch-level data and pitch-by-pitch performance metrics. Our goal was to more accurately understand which organizations have the highest quality of overall pitching talent. This also allows us to see what traits certain organizations may prioritize in the draft and international free agency.
For each organization, team-level metrics such as whiff and chase rate were calculated by aggregating the metrics of each pitcher, weighted by number of pitches thrown by each pitcher in the organization at the end of the 2024 season (after the trade deadline) to provide an overall assessment of the pitching strength and depth of each organization.
The overall organization’s Stuff+ number is a blended metric of each pitcher’s Stuff+ (based on our internal model). The resultant number was then scaled on a wRC+ scale where 100 is average and a standard deviation is 10 points.
Again, the Mariners were the best in the sport. Tied for first with the Baltimore Orioles at a 105.7 Stuff+.
This is all well and good—and it is good and important—but there’s an even more fundamental thing the Mariners have been able to do with their foundational rotation. It’s what everyone wants.
They keep dudes healthy.
I don’t like talking about it much in the same way I don’t say anything when a pitcher has a no-hitter going. No, of course what I say doesn’t have the power to magically cause something to happen. Probably not.
Anyway, Mariners pitchers post.
Nobody’s perfect and the Mariners obviously do have guys miss starts here and there. Sometimes it comes at the cost of dudes being yanked at 84 pitches but the Mariners have avoided the big blow.
And do you know how many times I thought Bryan Woo’s UCL was cooked? You probably do. A lot.
But it wasn’t and isn’t.
Knock on wood, put out only good vibes—the Mariners rotation has run out as good and complete a five-man rotation as possible, without any major injuries.
Is there anything that should matter more to Rōki Sasaki than staying healthy? Heck, even getting healthy may be the first checkpoint.
The Mariners offer an idyllic soft landing spot for financial and development reasons but are still competitive enough to offer…something much more.
The heart: ‘The LeBron James of Japanese Baseball’ is a dope nickname—so is that the level he wants to reach?
I’ve said it in so many contexts and I’ll say it here again. It sounds so obvious but is commonly overlooked: it matters if people like you. Doing things people like makes people like you. And people liking you matters.
The Mariners don’t…really have a great pitch for the heart. Which is…oddly the pitch? Bear with me.
The Mariners benefit greatly in the Japanese market by being closer to the other side of the Pacific Ocean than most of the baseball world. There are some teams closer, and the Mariners also get hit the other way by being less appealing to most of the Latin markets…and, well, most of this country, too. But here the Mariners get some geography help.
So you say hey, if we’re being optimistic, we’re saying Sasaki probably wants to play for a West Coast club. The East Coast is a long way away and the lights get awfully bright and hot real fast in New York and Boston and Philadelphia.
Alright, we’re thinking…Los Angeles (*2), San Francisco, San Diego…Arizona? They’ve been frisky. Maybe Texas or Houston, but that doesn’t feel right.
Anaheim’s gotta be out. We would’ve said that before Shohei but come on. Gotta.
San Francisco has weird vibes. Some of the early Buster Posey regime stories paint a picture of a back-in-our-day ethos a kid like Sasaki doesn’t need right now.
San Diego, you got me there. San Diego is fun as hell. They pack the park. They have Darvish but you’d be the top pitcher as soon as you were ready. And he’d help. But you will have to beat the Dodgers. And face them constantly.
Ah yes, the Dodgers. The Snell signing doesn’t mean anything. Like, 90 percent chance it does not impact their thinking nor reflect an option cut off. They’re the favorite until they aren’t.
But you won’t be the dude there. It’d be hard to be a dude on a roster like that one. And if you win it all, will it feel like you did? They just won their title, without you.
And they’re the class of baseball for a reason, for sure. I say “If winning a title is all you want…” as a Mariners fan like a dumbass, but maybe there’s something there to guys like this.
At 23 years old, with so much possibility ahead but so much of a story to start writing, you want to do your own thing.
Seattle is a safe landing spot, yeah. But it’s also a canvas with a lot of material to work with.
Seattle had Ichiro. The Michael Jordan of Japanese baseball. But he wasn’t a pitcher. And he wasn’t LeBron, either.
Julio Rodríguez has shown a star can shine bright on the national level even from the distant yonder of the Pacific Northwest. You’ll fit right in at the Some of the Best Pitchers in Baseball Factory; your catcher will make sure of it.
The organization will ensure you’re available and at your best. And if your best is as good as they say it is, there may be a Cy Young or two in it for you with the way the ballpark plays.
Maybe you want to be there in the big games in Dodger blue, pitching three innings out of the bullpen with a tired arm.
But maybe you want to be Roger Clemens in Boston. Pedro in Montreal. Randy in Seattle.
Listen, if you’re the missing piece that propels the Seattle Mariners to even an American League West title, you will be worshipped here.
And the path there in the division, with Sasaki, gets a lot more friendly. Where there were muddy rocks to climb over, there’d be a nice wooden stairwell freshly built by some Boy Scouts from Edmonds.
This time of year, everyone’s done their homework.
Jerry Dipoto and his Baseball Ops group knows he could get this guy for that guy. There’s a chance to pursue this guy if they want to go that route; the deal’s mostly there. They know if they put that guy on the table, this elite talent is as good as theirs.
They may and probably do know just how in they are on Rōki Sasaki, too.
Time will only tell. Who knows what Sasaki truly wants—what will be the ultimate decider.
Rōki Sasaki is appealing to every team in baseball. But not every team has what the Mariners can offer.
Maybe, no one does.