What to Expect from Cardinals Reliever Luis Gastelum

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What to Expect from Cardinals Reliever Luis Gastelum

Originally posted on New Baseball Media
By Chris Studley | Last updated Jul 8, 2026 6:00 PM ET

It was inevitable at some point that Cardinals pitching prospect Luis Gastelum was going to get a shot in the Majors this season. That time is now, as the Cardinals promoted the electric relief pitcher prospect on July 8.

A Look at Gastelum

Over the last two Minor League seasons, there have been very few relievers who’ve performed like Luis Gastelum, who may very well be the next notable potent arm to join the St. Louis bullpen.

After a very good season in Low-A in 2024, Gastelum skipped High-A and went straight to Double-A. Gastelum, as we noted in our 2025 offseason Minor League coverage, was impressive, to say the least. The righty posted the highest Whiff% (36.9%) in the Texas League last season.

He spent time both with Team Mexico in the 2026 WBC and with the Cardinals as a non-roster invite this past spring. Gastelum then moved to Triple-A Memphis, where he was impressive. Forty-nine strikeouts over 43.2 IP, along with a sub-3.00 ERA for the Redbirds as of July 8.

Gastelum went virtually untouched from June 1 onward. The right-hander tossed 15.1 scoreless innings in Memphis from that point forward, striking out 21 batters with just four walks.

It’s a four-pitch mix for the young reliever, a good thing to have in the modern age of baseball. Gastelum has two fastballs, one a sinker and the other a low-90s four-seamer that topped out at 96 MPH. Plus, a sweeper and his ace pitch, a low-80s changeup.

(via New Baseball Media)

The 24-year-old sported one of the dirtiest changeups in the upper Minors over the last two years. Just from looking at the vert/horizontal movement, one can see just how much sinking action he gets on the pitch. And, from a visual standpoint, you can also see why it’s so effective. Not only does he have the fastball to play off it but the movement, as well.

His changeup had a 45% swing-and-miss rate in Memphis. And, as one would expect, that pitch also sees plenty of usage against right-handed hitters.

Encompasses right-handed hitters only. (via New Baseball Media)

The Cardinals selected the contract of Luis Gastelum on July 8.

Analysis

Normally, a relief pitcher prospect moving up to the Majors wouldn’t garner a ton of attention. But Gastelum is different, especially with that jumping changeup that could make him an ace-in-the-hole for the Cardinals’ bullpen over the coming weeks and years to come.

Gastelum also comes up in what’s been a good year for St. Louis, thanks in large part to the emerging young guns, as well as a good overall bullpen that looks very different compared to what it did a year ago.

No Ryan Helsley, no problem. Riley O’Brien, now an All-Star, has emerged as a legitimate closer. Despite Matt Svanson, one of MLB’s top relievers from 2025, struggling this season, the likes of JoJo Romero, George Soriani, Justin Bruihl, and Gordon Graceffo have all filled innings effectively, too.

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

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