Three Underrated Seattle Mariner Pitching Prospects to Follow in 2025
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Modesto Nuts pitcher Ashton Izzi fires a pitch during a regular season minor league game. Credit: Ashton Izzi/Instagram [/caption]
The 2025 season is under two weeks away, and while fans of the Seattle Mariners should be excited for the upcoming campaign because of the elite pitching staff and a lineup that also exists (sorry), there’s also plenty of reason for long-term optimism as the Mariners currently have one of — if not the — best farm systems in all of Major League Baseball.
The reason for that public admiration has much to do with the “famous” prospects in the system like Colt Emerson, Cole Young, Harry Ford and more. But the Seattle system is much more than those names. Much, much more. There’s more quantity in this group than I can ever remember, and I’ve been doing this for far too long.
Yesterday, we took a look at the most underrated hitting prospects in the Seattle system.
Now it’s time to take a look at the hurlers. There’s a plethora of pitching prospects that aren’t getting the respect they deserve — at least in this writer’s opinion — but three in particular stand out as potential contributors for the Mariners in upcoming seasons.
Teddy McGraw, RHP
The Mariners 2023 MLB Draft class appears to be a special one, and not only are there several top prospects in the system from that year’s group, but the Mariners have already used three of those selections to acquire Randy Arozarena from the Rays. McGraw was also part of that class, and while it’s understandable why he hasn’t gotten the same level of fanfare as some of the other players procured, there’s plenty of reason for optimism in his right arm going forward.
McGraw slid to the third round of that aforementioned draft mainly because of availability. He underwent Tommy John surgery prior to the start of the campaign and didn’t pitch during his junior year. It’s what he showed prior to that operation — and a bit since he was selected — that makes him one of the most underrated pitching prospects in baseball, not just the Seattle system. The 6-3 right-hander has a heater that gets clocked up to 97 mph routinely, and the pitch gets the “bowling ball” designation because it offers a good amount of sink. He complements that heater with another plus pitch in his slider, and it’s a pitch he can locate for strikes or bury down in the zone. He also has shown the makings of a quality change, and while it doesn’t offer the same upside as his fastball/slider, it doesn’t have to in order to be a solid third option.
McGraw needs to improve his command and needs to have some success at the higher levels before getting too excited, but the stuff is here for him to be a mid-rotation starter at the highest level, maybe better.
Ashton Izzi, RHP
Izzi was taken in the fourth-round of the 2022 draft, and somewhat quietly put together one of the better pitching seasons of any prospect in the Seattle system. He did at as 20-year old while pitching for Low-A Modesto — not the friendliest of confines for pitchers, it’s worth nothing — and he forged a 2.89 ERA and .230 average allowed over 110 2/3 innings in his first full season of professional action.
A 6-3 right-hander, Izzi is still filling out his frame, but already offers two plus fastballs; a four-seamer that sits in the mid-to-high 90s that will touch 97 — sometimes higher — and a two-seamer that is lower in velocity but “heavier” in movement. His secondary offerings are a work-in-progress, but that’s not an insult and instead the reality of a pitcher of his experience. When everything is clicking, his slider is a 55-grade offering on the 20-80 scale, and his change is an average pitch to keep hitters honest, particularly those who hit from the left side.
The concern with Izzi is control, as 56 walks in those 110 2/3 frames isn’t ideal. But he’s made significant improvements each year since entering Seattle’s system, and there’s reason to believe that the Mariner pitching development system will work its magic on Izzi and have him ready to be a starter in the latter part of this decade.
Hunter Cranton, RHP
When the Mariners selected Cranton with the 91st pick of last year’s draft, the “consensus” was that this was a senior signing; a player that Seattle had to take to make sure it didn’t spend more than its allocated draft funds. While Seattle did sign Cranton for a paltry $50,000 — more than $750,000 below the number assigned to that pick — anyone who has seen Cranton pitch knows he’s much more than just a piece of organizational depth.
Cranton is strictly a reliever, as he only throws two pitches and doesn’t have the arsenal nor the command to be more than a reliever. That being said, there’s reason to believe he can be a high-leverage option in a bullpen someday. The former Kansas Jayhawk can get his fastball into triple digits, and he ranked in the top one percent of all collegiate hurlers in his ability go generate swing-and-misses with the pitch at 38 percent. On top of that heater, he has a slider that gets plus grades, and all it needs is more consistency for it to become a legitimate second out pitch.
Cranton has had issues throwing strikes — something all three of these pitchers have in common — and there’s considerably less ceiling in his right arm than Izzi and McGraw. But when your stuff is this good and you’ve generated misses with your arsenal at that level, you can’t help but be intrigued. It wouldn’t shock me at all if Cranton was helping Seattle by the end of 2025.
