Who Will Play First Base for the Diamondbacks in 2026?

Arizona Diamondbacks Have Questions at First Base

While it's true that starting and relief pitching are clearly the correct priority, the D-backs have other questions. They might have found an answer for every day third base in Blaze Alexander.

But following the trade of Josh Naylor to the Seattle Mariners, first base was a gaping offensive hole over the final two months of the season, creating questions about the position going forward.

Such large questions, in fact, that manager Torey Lovullo lamented that he didn't actually have a first baseman. Speaking on September 15, he said, "You know, we don't have a first baseman, right? This is crazy. We're in the middle of a pennant race, and this is where we're at."

At that point in time, Tyler Locklear had already gone down with injury a week before. Pavin Smith was on the injured list with an oblique strain. From September 7 onwards Lovullo was reduced to platooning utility men Ildemaro Vargas and Tim Tawa.

Pavin Smith hadn't played since August 27th, lost for the remainder of the season with an oblique injury.

The production received from those players from August 1 onwards was the worst in MLB, by a large margin. League average OPS from the position was .773 from that date forward.

The D-backs' first basemen combined to post a .560 OPS, ranking dead last in MLB, and 60 OPS points behind the 29th-ranked team.

Arizona Diamondbacks Internal Options for First Base

Looking closely at the internal options for the Diamondbacks going forward does not seem to provide a stable answer to the position.

Related Content: Diamondbacks Named Fit for Mets All-Star

Pavin Smith (LHB)

Smith, who will be entering his age-30 season in 2026, has a career .246/.330/.406 batting line, with a .736 OPS, or 102 OPS+ in 1,540 plate appearances.

That comes with a heavy platoon split, as he has a .772 OPS against right-hand pitchers but just .597 against left-handers. At this point in his career, Smith is strictly a platoon option.

Smith appeared to achieve a breakthrough with a very hot September in 2024, and got off to a hot start in 2025 through April 20 as well. From 9/1/24 through 4/20/25 Smith hit .333 with nine homers and a 1.115 OPS in 139 PA.

But that came with a near 30% strikeout rate, signaling a lack of sustainability to maintaining anything close to that level of production.

Over his final 222 PA in 2025 before his season ending injury, Smith slumped to a .222/.326/.360, .686 OPS batting line. He struck out 32.4% of the time.

While most of his playing time in 2025 came at DH, he did play 283 innings at first base but registered -2 Fielding Run Value from Statcast and -4 Defensive Runs Saved from Baseball-Reference.

Tyler Locklear (RHB)

Locklear had a failed call-up in 2024 with Seattle, batting .156 with a .536 OPS in 49 PA. A strong two-month run in Triple-A in 2025, following a tweak to his batting stance, put him back on the prospect map. That enticed the D-backs to ask for him as part of the Eugenio Suarez deal at the trade deadline.

Locklear, age 24, struggled again however, batting .175/.267/.262, .529 OPS in 116 PA. He managed three homers, but no other extra-base hits and struck out 43 times while taking just 10 walks. The defense was suspect as well, registering -2 FRV and -5 DRS.

He went down September 7 with an injury following a collision at first base, injuring both his elbow and shoulder. The news as reported yesterday by Alex D'Agostino was not good. He will require surgery for a torn left elbow ligament and a torn labrum. His availability to start the season on opening day is in question. The surgery will take place October 16 and there is no timeline for his return as of this writing.

Tim Tawa (RHB)

Tawa was called up early in his age-26 season to fill in for an injured Ketel Marte at second base. He played outfield as well, but after an initial hot streak, slumped badly at the plate and was sent back down to Triple-A Reno.

Shortly after the send-out, he suffered a broken rib on a hit-by-pitch, missing six weeks.

Finally healed, he was recalled to help out at first base after Locklear got injured. He never really got going however, batting just .205 with one homer in 52 September PA.

For the full year, Tawa hit .201/.274/.347, .620 OPS in 225 PA. He did hit seven homers, and has shown plenty of power in the minor leagues. He rated +2 DRS at first base this year.

Ivan Melendez (RHB)

Beyond the three players mentioned above, the next possible internal option could be Ivan Melendez. He reached Triple-A in 2025 at the age of 25. Previously plagued by very high strikeout rates over 30%, he managed to reduce that to 24.5% across two levels in 2025.

In 98 PA for the Reno Aces he posted a .292 average with three homers and an .830 OPS. While that may seem good on the surface, it amounted to a 94 wRC+ in the offense-rich environment of one of the best hitter's parks in the PCL.

Summary

If the Diamondbacks do not go outside the organization they will be hoping that at least one of the above players can take a step forward and seize the opportunity.

None were able to do so in 2025. In later articles here at Arizona Diamondbacks On SI, we'll dive into some of the more creative external options the team might consider to pursue.

Arizona Diamondbacks Latest News