D-backs Slugger's 2025 is Brutal Reminder of What Could Have Been

It was tough for Arizona fans to watch what happened after the deadline.

Arizona Diamondbacks' Josh Naylor bats against the Houston Astros in the first inning at Chase Field in Phoenix on July 23, 2025. | Rob Schumacher/The Republic / USA TODAY NETWORK via Imagn Images

The Arizona Diamondbacks were expected to be one of the teams in the thick of playoff contention in 2025. Clearly, that was not meant to be.

The D-backs loaded up on talent ahead of the season, but began to watch numerous key players go down to injury, or simply underperform. That led to a heartbreaking decision — GM Mike Hazen opted to trade many of Arizona's high-performing veterans at the Deadline to recoup prospect capital and reload for the future.

One such casualty was first baseman Josh Naylor. Naylor was acquired by Arizona in a trade with the Guardians and performed well for the first half. On an expiring contract, however, Naylor was dealt to the Seattle Mariners, where he became an instrumental part of Seattle's deep postseason run.

As Arizona Diamondbacks On SI continues to break down the individual seasons of every player that contributed to the 2025 D-backs roster, the below article will be updated with the proper links to every season review as they are published.

Related Content: Breaking Down Every Diamondbacks Player's 2025 Season

Arizona Diamondbacks 2025 Player Review: Josh Naylor

Josh Naylor statistics | Alex D'Agostino

Naylor was the model of consistency on the offensive side with Arizona. Over the course of his first full month (April), he hit .305/.374/.495, then followed it up with a bit of a down month in May, but still produced to the tune of a .284/.319/.440 slash.

The power-hitting personality Naylor was known for had given way to a more contact-hitting, on-base approach. While he certainly did not shy away from extra-base hits, they came more in the form of well-placed doubles to the gap.

He hit .311/.366/.486 in June, though he did miss some intermittent games with a shoulder ailment. He did not spend any time on the IL, however.

On July 24, Arizona swung the trade with Seattle. Over a week ahead of the official deadline, Naylor was sent to the Mariners in exchange for lefty reliever Brandyn Garcia and right-handed pitching prospect Ashton Izzi.

Naylor went on to put forward an even more impressive two months down the stretch for the Mariners, helping push them all the way to the ALCS. He hit to an eye-popping .340/.392/.574 with three homers in 12 playoff games — a harsh reminder of what might have been if several factors went Arizona's way in the regular season.

Josh Naylor: 2026 Outlook

Naylor, after his productive second half with the Mariners, earned a five-year, $92.5 million deal to remain in Seattle. He will not return to Arizona.

The D-backs' pitching prospects, however, could have an impact. Garcia emerged as a solid relief option at the MLB level toward the end of 2025. His high-octane stuff and overall performance tells a different story than the 5.84 ERA.

Izzi, meanwhile, pitched to a 3.58 ERA in six starts with the High-A Hillsboro Hops — an intriguing prospect, but still some time out from an MLB debut.