David Hagaman, Arizona Diamondbacks, High-A Hillsboro Hops, [Pitching Prospect Rank #66]

When I find myself trying to scout a diamond in the rough I like to lean on my familiarity with hitting mechanics, swing decisions, and discipline metrics. So allow me to do something completely out of my comfort zone. David Hagaman, a starting pitcher at High-A Hillsboro in the Diamondbacks system, is someone that I have pinpointed as a potential breakout sleeper for the 2026 season. 

Hagaman was a fourth round draft pick in the 2024 MLB draft out of West Virginia taken by the Texas Rangers. His 2024 campaign ended when he underwent a successful internal brace procedure on his throwing elbow, without having thrown a pitch in affiliated ball. In 2025 he was traded to the Diamondbacks in the trade that sent Merrill Kelly to Texas, and ranked as the Rangers’ thirteenth prospect at the time.  

Coming in at 6’ 4” and 215 pounds, he has a prototypical starters build despite having largely been a reliever during his time at West Virginia. Pitching exclusively from the stretch, he has a very repeatable delivery coming from the high ¾ arm slot. He shows a good tempo and was able to strike out hitters in the lower levels of the Rangers and Diamondbacks systems with all four of his fastball, slider, curveball and changeup. 

Receiving 55 grades across the board for the four seam fastball, slider, and changeup, it is quite clear watching him pitch that he has great feel and ability to generate swing and miss with these pitches. His fastball routinely hits mid 90s, getting up to 96-97 mph. His slider is a true slider, with a sharp bite to it. He shows decent feel for a changeup that runs to his arm side and gives him coverage against lefties. The curveball, which is not listed on many (if any) of his scouting reports, appears to be a true fourth pitch and more for show, but it did generate its fair share of strikes.

Discounting his handful of starts at Rookie ball, he had 10 starts between Single-A level Hickory for Texas and Hillsboro in the Diamondback’s system where he pitched a total 35.1 innings. For a career reliever in college, averaging ~3.2 IP per start is nothing to sneeze at. Factor in that he’s coming off internal brace surgery and that’s even more impressive. 

The most fascinating part of his profile, though, is in his command. Slapped with at best a 40 grade command tool, he has shown an incredible penchant for strike throwing. In his 5 starts at Hillsboro, he pitched 20 innings, struck out 27 batters and only walked FOUR. The career reliever pitched to the tune of a 0.75 WHIP while generating strikeouts at a stellar 12.2 strikeouts per nine (K/9) innings. 

That is a 0.1 lower WHIP than Tarik Skubal’s 2025 mark, and only a 0.3 lesser K/9 than Aroldis Chapman’s 2025 mark (insert obvious small sample size caveat here). 

All of this is simply to say that David Hagaman is one of my favorite pitchers to watch for 2025, and he definitely deserves to be owned in more than 0.91% of Ottoneu leagues… especially since I’m that entire 0.91%.