A's Top Prospect Jamie Arnold Sets Career High in One of His Best Double-A Starts

The southpaw looked sharp in his latest performance

Jul 28, 2025; West Sacramento, California, USA; Athletics 2025 1st round draft pick Jamie Arnold speaks with members of the media before the game against the Seattle Mariners at Sutter Health Park. Mandatory Credit: Sergio Estrada-Imagn Images | IMAGN IMAGES via Reuters Connect

The Athletics' top pitching prospect, left-hander Jamie Arnold, just turned in one of the strongest outings of his first season in the minors.

Arnold, MLB Pipeline's No. 2 prospect for the A's in 2026, tossed 5 2/3 scoreless innings for the Double-A Midland RockHounds on Wednesday. The 22-year-old only allowed two hits and two walks while striking out nine in Midland's 9-1 victory over the Frisco RoughRiders, the Double-A affiliate of the Texas Rangers.

Those nine strikeouts mark the most Arnold has recorded in a single game early on in his professional career. The young lefty's previous career high was eight punchouts, which came in another game against the RoughRiders on July 1. With a little over a month remaining in the RockHounds' season, the top prospect likely has just a few more chances to try to produce his first double-digit strikeout game in the minors.

How has Jamie Arnold pitched in his first season in the minors?

Feb 20, 2026; Mesa, AZ, USA; Athletics pitcher Jamie Arnold (75) poses for Photo Day at HoHoKam Stadium. Mandatory Credit: Rick Scuteri-Imagn Images | IMAGN IMAGES via Reuters Connect

The A's selected Arnold with the 11th overall pick in the 2025 MLB Draft out of Florida State University. And just like another early first-round pick from that draft class, Seattle Mariners left-hander Kade Anderson, the young southpaw has spent the entire 2026 season at Double-A so far.

Through the first 20 starts of his professional career, Arnold has a 3.84 ERA with 105 strikeouts in 96 innings. The 22-year-old faced some adversity in May, posting a 7.11 ERA in five starts. But outside of that rough stretch, he had a 2.95 ERA in April, a 2.31 ERA in June, and a 3.54 ERA in July. In fact, the top prospect gave up 20 earned runs in May but has allowed 21 earned runs the rest of this season combined. So, besides that one tough month, the young hurler has shown why he was such a highly touted draft pick last year.

The A's have already inserted one promising left-hander into their big league rotation this season in Gage Jump. If Arnold keeps pitching the way he has lately, he could be a candidate to make his MLB debut at some point next year. But first, he'll focus on finishing his first season in the minors on a strong note.