What to Expect from Giants Pitcher Carson Seymour

Originally posted on New Baseball Media
By Chris Studley | Last updated Jun 27, 2025 8:01 PM ET

On June 27, the Giants called up one of the best pitchers in the Pacific Coast League this season: Carson Seymour. Seymour, acquired three years ago, had himself a fine season and ranked as the league leader in strikeouts before joining a strong Giants pitching staff.

A Look at Seymour

San Francisco acquired Carson Seymour nearly three years ago in 2022, as part of a five-player trade that sent Darin Ruf to the Mets. The Giants picked J.D. Davis and former top Mets prospect Thomas Szapucki, plus two interesting ex-collegiate arms: former Xavier pitcher Nick Zwack and Seymour.

Seymour, a sixth-round pick from 2021, posted gaudy strikeout numbers in High-A before the trade and has steadily risen through the ranks since. And this season, Seymour proved to be highly successful in the hitter-friendly Pacific Coast League.

This season with Sacramento, Seymour struck out 83 over 74 innings, nine more than teammates Trevor McDonald and Carson Whisenhunt. Opposing batters hit .228 off Seymour. However, the 26-year-old posted a 1.35 WHIP, largely buoyed by 37 walks over 74 innings.

Seymour has a lot of weapons at his disposal, as he threw seven recorded pitches with Sacramento. The bread-and-butter pitcher Seymour relies on in his hard, mid-to-high-90s two-seamer that can have varying shapes. Sometimes, it rises. Other times, it’s more of a true sinker.

Carson Seymour 2025 AAA Pitch Movement 2025 Via New Baseball Media

On top of that pitch, he’ll work in a hard four-seamer that topped out at 99 MPH this season.

Additionally, Seymour possesses a sharp mid-80s slider with significant vertical depth. That pitch, which had a 35.1% Whiff% in 2025, had a mean average of -8.2 induced vertical action, almost 10” more drop compared to the league average.

He’s a heavy ground-ball pitcher, unsurprising given how much he leverages his sinker, changeup, and slider combined. His GO/AO ratio was 1.96 this season.

But as noted, Seymour’s walk problems have risen since moving into the upper Minors. He posted 4.0+ BB/9 rates in 2024-25. He doesn’t have a difficult-to-repeat delivery, though.

The Giants officially promoted Carson Seymour on June 27. In a corresponding move, Sean Hjelle was optioned.

Analysis

When the Giants traded Kyle Harrison and Jordan Hicks (IL) to Boston for Rafael Devers, the move did somewhat deplete their immediate pitching depth at the MLB level. However, teams have to give up to get — and the price, if Devers can provide the punch needed, was worth it.

However, there is the issue of how to piece together games now. Seymour, with a starter’s arsenal, can help out.

Now, to be clear, the Giants’ bullpen has been one of the best in baseball this season. Randy Rodriguez and lefty Erik Miller both have sub-1.00 ERA figures this season, while Camilo Doval and Tyler Rogers have helped hold down the late innings.

Depth, though, has never hurt anybody. And with Seymour, he can give teams a different look and possibly be an SP option down the line if needed. Right now, the Giants, led by Robbie Ray & Logan Webb, have a solid top-five but have seen Hayden Birdsong struggle as of late.

This article first appeared on New Baseball Media and was syndicated with permission.

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