Mitch Bratt Showed Something Strong in his Diamondbacks Debut

It wasn't a particularly lengthy outing, but it was one that showed signs of potential for future success.

On Wednesday evening, Arizona Diamondbacks leftt Mitch Bratt made his anticipated MLB debut against the St. Louis Cardinals at Busch Stadium after he was called up earlier in the day.

He only managed to pitch his way through three innings on 54 pitches on a short leash, giving up one run in the process. He had just returned from the minor league IL with a minor shoulder issue, and was not expected to throw much more than around 60 pitches.

There were signs of some growing pains, but also flashes of potential — potential for the Diamondbacks to have a solid young left-hander in their rotation in the future.

Diamondbacks' Mitch Bratt throws sturdy debut

Jun 24, 2026; St. Louis, Missouri, USA; Arizona Diamondbacks starting pitcher Mitch Bratt (60) pitches in first inning of his Major League debut against the St. Louis Cardinals at Busch Stadium. Mandatory Credit: Jeff Curry-Imagn Images | Jeff Curry-Imagn Images

Bratt gave up a pair of base hits (a single and a double) and a pair of walks. He picked up his first three major league strikeouts — two swinging and one looking.

Though Bratt is not a particularly hard thrower, and his raw stuff does not light up the analytics or the box scores, he was able to get seven whiffs on the night, despite only working his way through nine outs. Four of his whiffs came on the slider, which he threw only 10 times.

On the topic of velocity, there was not much of that. Bratt averaged 91.9, but there were a few instances of around 93, or even 94. A tick or two added to the fastball could benefit Bratt as he continues his development trajectory, but he'll never be a flamethrower.

That can work just fine when a pitcher's location is precise. Bratt did not necessarily live and die by pitches in the zone, but he did land more than a few balls on the outside edge of the zone, and even climbed the ladder for a few elevated-fastball swings.

Bratt, Arizona's No. 14 prospect, is just 22 years old, coming off an excellent season thus far in Triple-A Reno. He's got a 2.84 ERA in the offense-heavy Pacific Coast League, and now a 3.00 ERA after his first major league outing.

"I think the moment wasn't too big for him," said his father, Brian, speaking to D-backs.TV's Todd Walsh on the game broadcast. "I think I was more nervous than he was."

He certainly did did not look nervous. Bratt attacked hitters and pitched a confident first game. With both Michael Soroka and Ryne Nelson expected to miss a chunk of time with respective injuries, and Brandon Pfaadt still getting stretched out to starter's length, Arizona may very well see more than a handful of starts from Bratt.

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