Ryan Sloan Is Turning Heads - and Not Just Because of the Cal Raleigh Comparison
There are prospect updates that raise an eyebrow - and then there are the ones that make you do a double take and wonder if the Mariners just stumbled onto something special. That’s exactly where we are with 20-year-old right-hander Ryan Sloan.
Mariners President of Baseball Operations Jerry Dipoto recently made a comment that’s as funny as it is telling: Sloan, he said, “might have a larger lower half than ‘The Big Dumper’” - a nod to catcher Cal Raleigh’s famously sturdy frame. It’s a hilarious visual, sure, but it also hints at something deeper.
The Mariners aren’t just laughing at the size of the kid’s legs. They’re smiling because this 6-foot-5 righty is showing up to big league camp with more than just raw tools - he’s showing polish, poise, and the kind of stuff that makes player development folks lean in a little closer.
Sloan Isn’t Just Flash - He’s Showing Feel
It’s easy to get caught up in the radar gun numbers, and Sloan gave us a reason to do just that when he opened a live batting practice session by firing a 99 mph fastball to none other than Cal Raleigh. That’s one way to introduce yourself to the face of the catching room.
But the heat is only part of the story. According to MLB.com’s spring training notes, Sloan isn’t just airing it out - he’s commanding it.
That’s the part that has the Mariners buzzing. Dipoto even said that if you didn’t know Sloan had never pitched above A-ball, you wouldn’t be able to tell just by watching him.
His delivery is repeatable, his command is sharp, and he’s already throwing strikes with consistency.
Last season, Sloan threw first-pitch strikes to 73 percent of hitters - an elite number, especially for a young pitcher still learning how to navigate professional lineups. That kind of strike-throwing foundation is gold for a development staff. It’s why Seattle feels comfortable expanding his arsenal instead of just letting him ride the fastball-slider combo.
Building the Full Arsenal: The Mariners’ Starter Blueprint
The Mariners are known for their pitcher development, and Sloan is already being handed the blueprint. They’re working in a two-seamer, and they want him to lean more on his changeup in 2026 - a pitch that made up just 8 percent of his mix last season.
The goal? Build out a legitimate four-pitch mix that can play at the highest level.
And then there’s the slider. Oh boy, the slider.
In that same live BP session, Sloan finished off Randy Arozarena with a slider that had 20 inches of vertical break. That’s not a typo.
That’s movement you usually only see in video games. Mariners pitching strategist Trent Blank confirmed the number - and it’s the kind of pitch that makes hitters walk back to the dugout shaking their heads.
So… How Fast Is Too Fast?
That brings us to the only real question with Sloan right now: how aggressive should Seattle be with his development?
Keith Law recently noted that the only concern is how ready Sloan already looks. It’s not a matter of “if” he’ll be good - it’s about how fast you want to push a kid who’s already showing big-league stuff before he’s thrown a pitch above A-ball.
All signs point to Sloan opening the year at High-A, likely alongside fellow prospect Kade Anderson. That’s a must-watch rotation for fans in Everett - and a pretty good excuse to take in a game or two if you’re in the area.
Because this isn’t just about a funny comp to Cal Raleigh’s build. This is about a 20-year-old with a 99 mph fastball, a bat-missing slider with absurd movement, and the kind of pitchability that’s rare at this stage. If the Mariners can continue to shape his changeup and two-seamer into consistent weapons, they might be looking at their next homegrown frontline starter.
And if Sloan keeps trending this way? That Cal Raleigh comparison might end up being the least exciting thing about him.