Former Diamondbacks Reliever Makes Surprising Jump to Mexican League

One of Arizona's former relievers is taking a new opportunity, in a surprising new place.

Sep 16, 2025; Phoenix, Arizona, USA; Arizona Diamondbacks pitcher John Curtiss against the San Francisco Giants at Chase Field. Mandatory Credit: Mark J. Rebilas-Imagn Images | Mark J. Rebilas-Imagn Images

One of the Arizona Diamondbacks' more positive bullpen contributors from the 2026 season is moving on to a somewhat-surprising new pitching opportunities.

Right-handed relief pitcher John Curtiss, who appeared in 30 games in the latter half of the 2025 season, has signed a deal with the Mexican League club Charros De Jalisco, according to the transaction logs on Curtiss' MLB player page.

It's a bit of a surprise to see Curtiss sign with a Mexican League team, as opposed to signing with another major league club, or taking a minor league affiliated deal somewhere.

Former Diamondbacks pitcher John Curtiss signs Mexican League deal

Sep 20, 2025; Phoenix, Arizona, USA; Arizona Diamondbacks pitcher John Curtiss (46) pitches against the Philadelphia Phillies during the ninth inning at Chase Field. Mandatory Credit: Joe Camporeale-Imagn Images | Joe Camporeale-Imagn Images

Curtiss had been released from his minor league contract with the Triple-A Reno Aces on May 15, which, in and of itself was a bit of a shock. He held a 4.02 ERA in 15.2 Triple-A innings, which is a significantly above-average figure in the pitcher's nightmare that is the Pacific Coast League.

As a big-leaguer in 2025, he threw to a 3.93 ERA and 4.01 FIP in 36.2 innings, often providing multiple frames of work at once. So while Curtiss was never exactly the type of arm who would be expected to provide plenty of high-leverage work, or play a major part in the Diamondbacks' MLB bullpen, he was certainly one of the best depth options available at the Triple-A level.

If a slew of injuries or significant underperformance had struck Arizona once again, it was not out of the question that Curtiss might have seen another major league opportunity, even considering a relatively re-stocked D-backs relief corps.

Arizona did bring Curtiss back this offseason on a minor league deal, intentionally returning him to the organization — likely with a depth mindset. So when he was released, the obvious potential reason for that curious decision was that the right-hander had requested his release, hoping to find a path back to the major leagues with a different organization.

That may not have been the case after all, unless the plan was for Curtiss to take an international job in the Mexican Leagues. A deal with Charros De Jalisco implies there are likely no health concerns.

Jalisco placed sixth in the Mexican League north division in 2025, going 46-46 on the year.

Arizona's bullpen, meanwhile, has looked better in its current state than it did a year ago. They rank 17th in baseball with a 4.11 relief ERA coming in to Friday, and the eye test has matched a more proficient group of reievers, with both A.J. Puk and Justin Martinez returning from their injuries later this season.