Jose A. Ferrer is stepping into his first spring training with the Seattle Mariners, and the message from the coaching staff is loud and clear: “You’re a Mariners reliever now-pitch like one.”
That doesn’t just mean throwing hard, which Ferrer already does with a sinker that touches 98 mph and drops like it’s got a grudge against the dirt. It means leaning into the Mariners’ pitching identity-mixing movement, deception, and sequencing to keep hitters off balance. And for Ferrer, that means unlocking the full potential of his slider and changeup.
The Mariners Want More Than Just a Sinker
Ferrer came over from the Nationals with a reputation as a sinker-first guy. In Washington, he leaned heavily on that pitch, using it to generate ground balls and jam hitters.
But in Seattle, that approach is just the starting point. Pitching strategist Trent Blank laid it out plainly: the Mariners believe Ferrer has more in the tank.
“The present stuff is there. It’s a real fastball, a real sinker, obviously, that’s (his) carrying trait,” Blank said.
“He’s always had the slider, and he has a changeup that he’s developing. Those are two things we’re going to see if we can maybe up the usage a little bit…”
That’s not just coach-speak. It’s a roadmap.
And while Blank called the changeup a “developing” pitch, the numbers from last season suggest the opposite. Ferrer actually threw the changeup nearly three times as often as the slider-21.9% versus just 7.5%.
So if the Mariners are pushing him to use the slider more, it’s because they see something special there.
A Slider That’s Already Flashing Nasty
And they might be right. In limited action last season, Ferrer’s slider was quietly devastating.
Hitters went just 2-for-19 against it, striking out 12 times. That’s a 52.5% whiff rate-good for top-10 among all sliders thrown at least 50 times.
The pitch isn’t flashy in terms of movement metrics. It doesn’t have elite horizontal sweep or vertical drop.
But what it does have is velocity-averaging 89.7 mph, second only to Tarik Skubal among left-handed sliders-and deception. That combination, especially when paired with a high-90s sinker, makes it a problem for hitters who already have their hands full.
The novelty factor may have played a role in the pitch’s success last year. But even if hitters start to see it more, it’s not like they’ll be able to sit on it. Ferrer’s sinker is the main course, and the slider and changeup are the side dishes that make the whole meal unpredictable.
Built for the Mariners’ Pitching Philosophy
Seattle’s bullpen has carved out a clear identity over the past few seasons. They don’t chase strikeouts with straight four-seamers the way some teams do.
In fact, their relievers threw four-seamers just 25.8% of the time last year-26th in the league. Instead, they lean heavily on sliders and pitches with movement.
Their 32.3% slider usage ranked third in MLB.
That’s the mold Ferrer is being asked to fit into. And based on what we’ve seen, he might be a perfect match.
Low Risk, High Ceiling
It’s worth remembering that the Mariners gave up a promising young catcher in Harry Ford to get Ferrer. But even with that price tag, they’re not putting all their eggs in one basket. Gabe Speier is still around as the primary left-handed option in the bullpen, which gives the Mariners some flexibility as Ferrer settles in.
If Ferrer takes a step forward-if the slider becomes a real weapon, and the changeup continues to miss bats-he could be a major piece in a bullpen that’s already one of the most creative and effective in baseball. If not, Seattle still has depth to fall back on.
But make no mistake: the Mariners see something here. And if they’re right, Ferrer won’t just be another arm in the bullpen. He’ll be a problem for hitters all season long.