Jamie Arnold has yet to throw a pitch in a regular season game since turning pro last summer when the A’s selected him with the No. 11 overall pick in the MLB Draft. The A’s also seem to be ready to challenge him after Gage Jump flew through the minors last season while also making his debut.
According to MartÃn Gallegos of MLB.com, Arnold, the left-hander out of Florida State, will be starting his pro career in Double-A in 2026. Last year the A’s began Jump’s journey in High-A, where he held a 2.32 ERA across six games (five starts) spanning 31 innings, before he was promoted to Double-A Midland in mid-May.
Jump would be pitching two to three innings per appearance by July so that his innings pitched didn’t get out of control. All in all he finished with a 9-7 record across both levels and posted a 3.28 ERA with a 1.10 WHIP across 112 2/3 innings. It was a stellar debut season that also landed him as the A’s No. 3 prospect heading into this season, and the No. 57 prospect in MLB.
Arnold is already starting in a little better spot, both in terms of rankings (No. 2 in A’s system, No. 41 overall) as well as being a first-round selection. It also doesn’t hurt that in his three innings of work this spring, he held a 3.00 ERA, giving up three hits, walking a pair and striking out four. Double-A should be a challenging assignment for him, but also a good learning experience.
The A’s are also seemingly moving their top prospect, Leo De Vries fairly quickly, with the 19-year-old appearing slated to begin the season in Triple-A Las Vegas.
How quickly can Arnold be in Sacramento? 
Jul 28, 2025; West Sacramento, California, USA; Athletics 2025 1st round draft pick Jamie Arnold walks onto the field before the game against the Seattle Mariners at Sutter Health Park. Mandatory Credit: Sergio Estrada-Imagn Images | Sergio Estrada-Imagn Images
The easy answer here is that it will depend upon how he’s pitching. If he’s dominating, the A’s seem to be showing that they’re willing to move him through the system quickly.
The deeper answer is that we could be looking at a September call-up situation, if things go well for everyone. To start the season, the A’s pitching staff is fairly healthy, so there is no immediate need for him. He also needs some time to develop in the minors.
Plus, Jump will be a level above him, starting the year in Triple-A Las Vegas. If he continues pitching like he has been in green and gold, then he could be up as soon as there’s an opening. Jump figures to be near the top of the starting pitcher depth chart in the minors. He likely gets the call before Arnold, which complicates the FSU left-hander’s path a touch.
That said, perhaps six to eight starts in Midland before spending another two to three months in Vegas would put him right around a September call-up situation. That would leave the A’s with an open roster spot where he could certainly help them push towards a postseason berth, or just get his feet wet to give the front office an idea of what they have to work with ahead of 2027.
How the A’s season is going could be another determining factor here.
How Arnold develops this season, and how quickly more specifically, could end up having a big impact on the A’s offseason plans. With Luis Severino able to opt out of his contract at the end of the year, Aaron Civale set to re-join the free agent market and Jeffrey Springs having a $15 million club option for next year, the rotation could look very different in 2027.
How the A’s address those needs next winter could depend upon Jump and Arnold, among other starter options.
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