Diamondbacks Top Prospects #8: RHP Landon Sims

The former National Champion closer will try to make it as a starter in the pros.

Name: Landon Sims

Age: 21

Position: Starting Pitcher

Acquired: 2022 MLB Draft, Competitive Balance Round A (34), $2.347M signing bonus

Tools: Fastball 65, Slider 70, Changeup 40, Command 50, Overall 50

Sims has an explosive fastball with a high spin rate and carry at the top of zone that sits mid 90s and tops out around 98 MPH. He also commands arguably the best slider in the Diamondbacks system, averaging in the mid 80s with a lot of late and horizontal sweep. Those two pitches are already flashing double-plus and are good enough for him to develop into a big league pitcher. His changeup significantly lags behind his other two pitches, but will be key for him to develop if he wants to be a big league starter. He may want to look into adding a fourth pitch with the intention to use it against left-handed hitters as a hedge if the changeup never develops.

In terms of makeup, Sims gets an 80 grade due to his rabid competitive nature and how he controls the pace in at-bats. Rob Friedman, known as the Pitching Ninja on Twitter, refers to him as a pace of play enforcer. 

ETA: 2025

Risk: Very High

Top 30 List

2022 Overview

After a successful run as the closer for a National Champion Mississippi State squad, Sims was elevated to be their Friday night starter in 2022. He made three electrifying starts, going 0-2 with a 2.87 ERA, with a 27/2 strikeout to walk ratio in 15.2 innings. In his start against Tulane on March 11th, he tore the ulnar collateral ligament in his right elbow and required Tommy John surgery three days later. He was one of many college arms to go down with a significant arm injury in the 2022 draft class, causing his stock to fall from a potential Top 10 selection to the 34th pick. The D-backs called his name with the 34th overall pick, looking to buy low on a pitcher who will either start or close in the big leagues. 

2023 Overview

Sims will likely finish his rehab and return to the mound early in the 2023 season. The player development staff will carefully monitor his workload, which may increase to somewhere around 80-90 innings. The goal will be to get him up to at least 150 innings by 2025 so he can work his way into a big league starter workload. He may start the year with Low-A Visalia to see how his stuff looks for a few starts before moving up to High-A Hillsboro for the majority of the season. It would not shock me to see his season end with Double-A Amarillo, in order to create a challenging environment for him.

MLB Projection

Sims currently is a difficult projection long term, but the two most likely outcomes would be happily welcomed on the big league roster. If he stays injury-free and is able to successfully build up to 150 innings in the 2025 season, he likely ends up as a middle of the rotation arm with an elite two-pitch mix of fastball and sliders with the occasional changeup. If there is even one injury that causes him to miss significant time and makes him unable to catch up in the Arizona Fall League, the D-backs might look to quickly convert him back to a high leverage reliever. I have no doubt Sims will develop into a key pitcher for the D-backs if he's healthy, the only question is if he's starting or ending games.