Who Should Be the D-backs’ DH to End 2025? Pavin Smith or Adrian Del Castillo?

With 45 games left in 2025, the Diamondbacks face a key choice: resume Pavin Smith’s DH role or accelerate Adrian Del Castillo’s development. This decision will shape not just the season’s end but also hint at Arizona’s 2026 roster plans.

D-backs manager Torey Lovullo told reporters on Sunday that Smith is one of three injured veterans who will embark on a rehab assignment this upcoming week. He’s been out since July 5 with a right oblique strain, which has allowed Del Castillo to face major league pitching. With his return imminent, the organization is having conversations about what to do with the DH position to close out the season.

The choice between Smith and Del Castillo is between the devil you know and the devil you don’t know. Smith has a longer track record at the major league level, with more than 1500 plate appearances compared to Del Castillo’s 143. Just this season alone, the gap is 264 to 49. With that small of a sample size, it’s unlikely that the team will deviate from their original plan at the DH spot.

We’ll take a look at Smith’s 2025 performance, the D-backs’ most likely decision on Del Castillo, preview both players’ outlook in 2026, and discuss the long-term future at the DH spot, although we all know that answer.

Pavin Smith’s 2025 Performance

If we go back to April 23, such a decision wouldn’t be on anyone’s radar. A strong finish to the 2024 season earned Smith the strong side of the DH platoon, giving the D-backs the confidence they’d be fine letting Joc Pederson walk. Up to that point, he was slashing .397/.500/.759 with four home runs in 70 plate appearances.

However, Smith has been in a deep slump. In the next 57 games, he’s hit just .213 with four home runs and a .660 OPS. His strikeout rate has spiked, with 64 punchouts in 194 PA (33.0%). Teams are attacking him with more breaking balls, pitches he’s consistently struggled against throughout his career. With more swing-and-miss in his game, that has negatively impacted his ability to be an effective middle-of-the-order bat.

When you add up those two stretches, Smith has been better than the average hitter. While propped up by a .379 average on balls in play, he’s still producing a .261/.371/.446 slash. FanGraphs rates his offense to be 29% better than the average hitter with a 129 wRC+.

Digging deeper than the surface stats, it’s still evident that Smith does two things exceptionally well. He makes solid swing decisions, with a 22.4% chase rate that ranks in the 82nd percentile among MLB hitters. It’s led to a 15.2% walk rate, which is one of the best in the game. However, he ranks in the sixth percentile in whiff rate (32.7%), which is fueling his high strikeout rate.

It’s those particular metrics that could lead to a change of direction in his role. His quality of contact is otherwise solid, with a 45.7% hard-hit (exit velocities of 95.0 MPH or greater) rate and an 11.0% barrel rate. However, the high strikeout rate has negatively affected his expected stats. On the season, Smith has a .224 xBA, .412 xSLG, and a .331 xwOBA. His xwOBA on contact hasn’t drastically declined, going from .459 in 2024 to .430 in 2025.

What Will Happen with Adrian Del Castillo?

The likelihood that Del Castillo wrestles the DH job from Smith was always going to be very low. His only chance was if he got extremely hot at the plate to the point that the organization could not simply ignore him. That didn’t happen, as he limped to a .255/.265/.383 slash this season, including a monster game against the Rockies on August 10th.

Del Castillo’s swing decisions are much worse on a rate basis compared to Smith’s. While his strikeout rate is only one percentage point worse in comparison (32.7% vs. 31.2%), he’s chasing out of the zone 34.7% of the time. That’s led to a microscopic 2.1% walk rate on the season. He’s hitting the ball hard, as evidenced by a 50.0% hard-hit rate and a 6.3% barrel rate. But then again, we’re talking a sample size of 183 pitches and 32 batted balls.

What will likely happen as a result of Smith being activated from the 10-day injured list is that Del Castillo is optioned to Triple-A Reno. As strictly a left-hand DH option, he does not fit the current roster construction and is competing against a more established player for the same role.

While I disagree with the idea of sending him down because he’s a prospect whom the team needs to evaluate before the end of the season. They might not be willing to risk exposing backup catcher José Herrera, who’s out of options, to waivers to keep him on the roster. Del Castillo has only caught one game (July 30th at Detroit) this season at the major league level, so it’s obvious they don’t see him as an option behind the plate.

2026 Outlook for Both Players

Smith will enter his second season of arbitration eligibility, as I expect the team to build with more proven options for 2026. That likely means Smith begins the season as the strong-side DH platoon bat.

For Smith, he can establish a stronger grip on the role by making efforts to cut his strikeout rate if he can maintain the same contact quality. His full-season numbers will not recover with only 150-175 PA left. The key will be getting it down to the 20-25% range down the stretch. If he does that, there’s no question he’ll reprise his 2025 role to open 2026 due to his relatively cheap salary compared to free agent options.

However, if he’s unable to do so, the team could look to free agency to solve that problem. A poor finish to the season could result in Smith, who is out of options, being non-tendered. It’s a very low risk of happening in the first place. Should that happen, then they should just ride or die with Del Castillo in that role.

For Del Castillo, he’s going to have to prove he can stick behind the plate. Between the more proven bat in Smith and a looming roster crunch involving the infield that will start next season, his path to a full-time DH role could be cut off. The opportunity for him to make a difference is at catcher, as a high-usage backup to the oft-injured Gabriel Moreno. José Herrera’s declining defense at the plate will certainly have the organization re-evaluating the position going into the winter.

There’s not much more he can prove in Triple-A, but he serves as a Smith insurance policy for the club. He’ll have two options remaining in 2026, allowing them to shuttle him up and down the roster. The organization needs to prioritize catcher defense as his pathway to playing time, as he certainly has enough of a stick to handle the role. At the same time, improving the chase rate to a more acceptable level. In a more ideal situation, he gets a runway to consistent playing time in 2026 behind the dish.

Long-Term Future of the DH Position in Arizona

The long-term situation for both Smith and Del Castillo is that neither player will likely be handling that role beyond the 2026 season. The changing roster dynamics regarding the state of the infield over the next 12 months will result in Ketel Marte becoming a full-time DH, with the rest of the infield shaking out after a survival of the fittest. The infield itself deserves a separate piece, with the sheer number of young players and prospects expected to fill the gaps.

As a result of what will likely happen, the D-backs could dangle Smith as a trade target the next two winters in search of bullpen help. Del Castillo, only being 25 and having the full six years of control, has more trade value. If the organization doesn’t see him as a catcher, then he’s more valuable as a trade chip to land more impactful pitching.