BA Grade/Risk: 50/Medium

Track Record: A multi-sport athlete in high school and initially a two-way player at Ball State, Jameson focused his attention solely on pitching during his draft-eligible sophomore year and took off. He turned himself into the program's best pitching prospect since Bryan Bullington went No. 1 overall in 2002. Jameson was named the 2019 Mid-American Conference pitcher of the year, setting a conference record with 146 strikeouts in 91.2 innings. He steadily climbed through the D-backs' system, reaching the majors in 2022 and turning in four impressive starts late in the year.

Scouting Report: Jameson has a big fastball that averages close to 97 mph and can occasionally reach triple-digits. Hitters can square it up on occasion, prompting him to adopt a two-seamer that has turned into a weapon. It sits closer to 94 mph with late, boring action that gets both ground balls and whiffs. His slider is a swing-and-miss pitch with sharp, late life, but he can also vary the speed and shape on it depending on the desired outcome. His curveball and changeup are average at best, pitches he uses primarily early in counts. Jameson has more control than command, but both have improved, as has his willingness to attack hitters with more than just his fastball. He is undersized, but he has a lightning-quick arm and is a terrific athlete. He is one of the fastest runners in the organization.

The Future: Jameson's performance in MLB at least temporarily put to rest questions about a move to the bullpen, but he still might need to refine his command to remain a starter. He figures to come to camp with a chance to win a rotation spot or put himself in position to claim one when a need arises.

Scouting Grades: Fastball: 65. Curveball: 50. Slider: 70. Changeup: 50. Control: 50