Who is Mitch Bratt, and why is he starting for the Diamondbacks?

For the second time within four days, the Arizona Diamondbacks will start a prospect making his MLB debut on the mound.

Left-hander Mitch Bratt was on the taxi squad on Tuesday with the possibility that he would start Wednesday’s game against the St. Louis Cardinals. Manager Torey Lovullo announced that Bratt will indeed be the guy after Tuesday’s ballgame.

Bratt will be the second pitcher to debut this season after Jose Cabrera’s electric first outing on Sunday. Bratt will also be the sixth player to make his MLB debut for the 2026 Diamondbacks.

With injuries to Ryne Nelson and Michael Soroka — paired with Brandon Pfaadt still getting stretched out in Triple-A Reno — the Diamondbacks have had to turn to youngsters to fill starts around Zac Gallen, Merrill Kelly and Eduardo Rodriguez.

Who is Mitch Bratt?

Bratt is a 22-year-old southpaw whom the Diamondbacks acquired at the trade deadline last summer.

The D-backs traded Kelly to the Texas Rangers for Bratt and fellow pitchers Kohl Drake and David Hagaman. Now, two players traded for each other will pitch in the same rotation less than a year later.

Bratt is 6-foot-1 and does not thrower harder than a low-90s mph fastball, but his calling card is pounding the strike zone. In 44.1 innings for Reno, Bratt has walked 12 batters with 42 strikeouts, which has led to a WHIP of 0.95.

That’s critical in a place like Reno where balls carry and walks will come back to haunt you. Bratt has kept his ERA down to 2.84, the lowest ERA in the Pacific Coast League with a minimum of 40 innings.

“He attacks the zone, throws a ton of strikes,” Reno pitching coach Jeff Bajenaru told Arizona Sports. “His fastball is low 90s, which you think doesn’t play in today’s game, but it does play. He’s got deception. He moves quick. He’s got some natural cut to his fastball, which helps. It’s really late and can get it in on the hands of righties. It’s a sneaky 90-91, for sure.”

Bratt went on the injured list with a minor shoulder issue on June 2, and he returned for a start last week.

He threw 48 pitches in four innings during his return.

Statcast registered five pitches in Bratt’s last start: four-seam fastball, curveball, slider, sinker and changeup. His fastball averaged 91 mph.

“He’s just continued to do what he’s always done, just attacking the zone relentlessly,” farm director Chris Slivka told Arizona Sports before the injury.

“Commanding the fastball. The velocity is starting to climb up a little bit more to last year’s norm. He’s adjusting as a young pitcher at that level and also sliding into a five-man rotation for a full season. He’s done a good job landing all his pitches in the strike zone. I think we’re continuing to emphasize utilizing the entirety of his mix so that he can really keep hitters off-balance. He’s done a great job competing at that level and continued doing what he’s always done, which is pound the strike zone.”

Unlike Cabrera, who was considered under-the-radar before his debut, Bratt is generally ranked as one of Arizona’s better pitching prospects.

MLB Pipeline ranked Bratt 14th in Arizona’s farm system, sixth among pitchers. FanGraphs placed Bratt 20th in its preseason rankings, while The Athletic’s Keith Law had him 14th.

The D-backs selected Bratt for the 40-man roster over the offseason as Rule 5 Draft protection.

Bratt is from Newmarket, Ontario, Canada and represented his home nation in the 2023 World Baseball Classic as a 19-year-old. He opted not to do so again this past spring in order to get acclimated in his first camp with the Diamondbacks.

The Rangers picked Bratt in the fifth round of the 2021 MLB Draft straight out of Georgia Premier Academy.

Mitch Bratt (@WVBlackBears '21) lowered his ERA to 1️⃣.5️⃣4️⃣ yesterday five shutout and hitless innings.🐻

𝗚𝗮𝗺𝗲: GS, 5 IP, 0 H, 0 R, 3 BB, 3 K
𝗦𝗲𝗮𝘀𝗼𝗻: 3 GS, 11.2 IP, 1.54 ERA, 8 K, 0.94 WHIP, .132 BAA

The former Black Bears left-hander is the @Dbacks No. 1️⃣4️⃣ prospect… pic.twitter.com/xi1Js9BwqP

— MLB Draft League (@mlbdraftleague) April 15, 2026

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