Diamondbacks Release Veteran Pitcher

One of Arizona's arms has been released.

Sep 2, 2025; Minneapolis, Minnesota, USA; Minnesota Twins relief pitcher Thomas Hatch (56) delivers a pitch against the Chicago White Sox in the sixth inning at Target Field. Mandatory Credit: Jesse Johnson-Imagn Images | Jesse Johnson-Imagn Images

The Arizona Diamondbacks have parted with one of the arms in their system.

According to the transaction log on his MLB player page, right-handed pitcher Thomas Hatch has been released from the Diamondbacks' organization. He'll depart the Triple-A Reno Aces.

Rotational depth has begun to dwindle for Arizona in recent days. With Hatch's release they'll lose one of their veteran depth options.

Diamondbacks release Thomas Hatch from organization

Feb 18, 2026; Scottsdale, AZ, USA; Arizona Diamondbacks pitcher Thomas Hatch (59) poses for a photo for MLB media day at Salt River Fields at Talking Stick. Mandatory Credit: Allan Henry-Imagn Images | Allan Henry-Imagn Images

Hatch, 31, is a veteran of five major league seasons. He was originally drafted by the Chicago Cubs, but spent his first three (short) MLB campaigns with the Toronto Blue Jays.

He'd only made 51 career appearances in the majors, mostly as a long reliever with an occasional spot start. The Diamondbacks inked him to a minor league contract ahead of the 2026 season; he'd most recently made 11 appearances (33 innings) with the Minnesota Twins the season prior.

Hatch did not break camp with the Diamondbacks after allowing three runs in five innings during big league spring training. Once he landed in Triple-A Reno, he was used entirely as a starting pitcher. Hatch made 11 starts for the Aces, pitching to a 4.01 ERA in 51.2 innings.

That number doesn't stand out too much, but it's significantly above average for the Pacific Coast League, where the average ERA is 5.47. The elevation in Reno can often diminish a pitcher's stuff, as well. Hatch's ERA is backed by a 4.52 expected ERA, so it's not a dishonest ERA.

Though it was never quite expected that Hatch would become a serious major league contributor for the Diamondbacks, there is always a need for pitching depth. If Arizona ran into some injury trouble, or began to see a large decline in results, Hatch may have been a veteran option worth taking a flier on at the big league level.

So while it's not an earth-shattering transaction, it does ever-so-slightly chip away at a rotational depth chart that has already sustained some major blows in recent days.

Diamondbacks rotation depth thinning out

Arizona Diamondbacks manager Torey Lovullo and pitcher Corbin Burnes (right) during spring training workouts on Feb. 10, 2026, at Salt River Fields in Scottsdale. | Rob Schumacher/The Republic / USA TODAY NETWORK via Imagn Images

Presumably, part of this equation is the fact that the team made the decision to send right-hander Brandon Pfaadt down to Triple-A, which may have made Hatch the odd man out of the Reno Aces' staff.

Pfaadt, who had been converted to a major league reliever (without much success), will be stretched back out as a starter.

But the Diamondbacks have taken some hits to their rotation depth, as well. Right-hander Cristian Mena, who was rehabbing a shoulder injury, will undergo surgery that is likely to end his season.

Meanwhile ace Corbin Burnes, who was expected back around the time of the All-Star Break, suffered a Teres Major strain while rehabbing, and may be held out until September or longer.