D-backs Top 40 Prospects in 2024: No. 18 Landon Sims

The reliever had a major year out of the bullpen and showcased his future closer ability and has the chance to debut in MLB next year

Jun 30, 2021; Omaha, Nebraska, USA; Mississippi St. Bulldogs pitcher Landon Sims (23) pitches against the Vanderbilt Commodores in the eighth inning at TD Ameritrade Park. Mandatory Credit: Steven Branscombe-Imagn Images / Steven Branscombe-Imagn Images

This article is part of a series reviewing the seasons of the top 40 prospects still in the Arizona Diamondbacks system as of the end of 2024.

Landon Sims, Right-Handed Reliever, DOB: 01/03/2001, 6'2, 227

Acquired: Competitive Balance Round-A Pick 2, 34th Overall in 2022 MLB Draft

The Arizona Diamondbacks drafted Landon Sims out of the 2022 MLB Draft with the 34th overall pick out of Mississippi State even though Sims was recovering from Tommy John Surgery that would wiped out his 2022 and early 2023 seasons.

The team signed him to an above-slot bonus of $2,347,050. In 2023, he pitched in the Complex League and in Single-A as he got his feet wet in professional baseball and ensured a healthy off-season.

In 2024, he started the season off with the Visalia Rawhide where all he did was dominate opposing hitters.

Despite recording a 4.38 ERA over 16 games and 24.2 innings, Sims had a 3.83 FIP, 3.46 xFIP, and walked just 14 batters against 40 strikeouts. Opponents were lucky against Sims as they had a .375 BABIP against him.

Sims' full potential came unleashed over his final three outings with the Rawhide. Over his final four innings, he allowed three walks, no hits, and struck out an eye-popping 10. 10 of his final 12 outs came via the punch-out.

That was enough for Arizona to say that he was ready to move up to High-A and pitch with the Hillsboro Hops.

There was no adjustment period for Sims with the Hops as he struck out five in his first 2.2 innings. That set the stage for a massive final two months or so of the season.

From June 13 to August 17, Sims recorded a 1.32 ERA over 27.1 innings. He gave up only 22 hits and 12 walks and struck out 38. His fastball and wipe-out slider simply overpowered these High-A hitters.

However, he did face a challenge in his next appearance on August 20 as he gave up five hits and four runs over just 0.2 innings.

Yet, he took it in stride and continued excelling after that appearance and posted a 0.00 ERA over his final five games and six innings. He walked two and struck out seven.

In total with the Hops, opponents had just a .666 OPS over 34 innings and 25 games. His ERA was 2.12 and he walked 14, but struck out 45. His FIP was an outstanding 2.76 and xFIP was 3.43.

He's a strikeout merchant as in Single-A, his strikeout rate was an absurd 37.4% and in High-A, it was 30%. Meanwhile, his progress in controlling walks was encouraging. At Single-A, it was somewhat high at 13.1%, but improved to 9.3% in High-A Hillsboro. The average walk rate last year was 9.9% in tge Northwest League.

His fastball, cutter, and slider have all developed into MLB-quality weapons that has him firmly in the picture for future late-inning appearances for the D-backs for the rest of this decade. That's already started in the minor leagues as he finished seven games and recorded two saves.

MLB Pipeline gave his fastball a 60 grade on the 20-80 scale and gave his slider a 60 grade too. Both are decidedly above average and could even continue to get higher on the scale as he develops into a better pitcher. He is just 23 years old.

If he can add a change-up to his toolkit to use against left-handed pitchers, Sims will be a complete reliever that should have no problem pitching routinely in the 7th or 8th inning. If he can handle the pressure, the 9th inning would be fine too.

His comparison to a pitcher in MLB would be that of Kevin Ginkel as they throw similar pitches in similar speeds and he has the potential to match what Ginkel has done the past couple of seasons in the Majors.

2025 Outlook

It would not be a surprise if the Arizona Diamondbacks have Landon Sims start the 2025 season in Double-A with the Amarillo Sod Poodles. There's not much more he has to accomplish in High-A and hasn't shown a reason needed to stay there any longer.

Sims has the chance to make his MLB debut in the second half of next year if he performs as expected. If he starts the season in Double-A and excels there, it wouldn't be a shock if Arizona then promotes him quickly to Triple-A.

This happened with Kyle Amendt who went from High-A to Triple-A over a couple of months. Relievers pitch more often and can move through levels quicker than most other players.

If Sims does well in Triple-A and the D-backs find themselves in need of a bullpen arm, it wouldn't be a surprise if Sims gets the call.

2025 is a big year for Sims too as it is the final year before he is Rule-5 Draft eligible. That means that he needs to prove to the Diamondbacks that they need to add him to the 40-man roster to protect him from being taken by another team.

That also incentivizes Arizona to aggressively promote him and get him in the Majors as soon as possible aside from his ability to dominate out of the bullpen.

It won't be long until Sims is pitching out of a lethal Arizona bullpen along with Kevin Ginkel, Kyle Amendt, Justin Martinez, A.J. Puk, and company.

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