Name: Drey Jameson
Position: Starting Pitcher
Acquired: 2019 MLB Draft, Compensation 1st (34), $1.4M signing bonus
Grades: Fastball 65, Curveball 50, Slider 60, Changeup 50, Command 50, Overall 55
Jameson features two different fastballs, a 4-seamer with a lot of ride that sits in the mid 90s that can top out at 100 MPH, and a sinker that has a lot of arm-side run that makes it a legit out pitch. The 4-seamer has a spin rate in the 31st percentile amongst big league pitchers, but is very efficient with a 91% active spin rate. His sinker is a legit double-plus pitch, with the ability to not only get ground balls at a prolific rate but also a swing-and-miss offering he can feature. He only recently picked up that pitch, learning how to throw it from former Diamondback Matt Peacock this spring.
Jameson's best secondary pitch is a slider, which tunnels well off both of his fastballs. The pitch is also a put-away offering, with 46% of the swings against the pitch coming up empty. His changeup is a complementary third pitch, with a similar movement profile and spin axis to his sinker. It's more of a change of pace offering than a legitimate out pitch, but has the potential to develop into one under the right tutelage.
Jameson opened up the year with Double-A Amarillo, but was quickly promoted to Reno after back to back starts where he flirted with a no-hit bid. Reno proved to be a challenging environment, as Jameson had a 6.95 ERA in Triple-A at the time of his call-up. Home runs were the main culprit, as his HR/9 jumped to 1.66 and 21.4% of the fly balls he allowed left the ballpark. The Pacific Coast League is notorious for favoring hitters, so despite the ugly run prevention numbers the D-backs felt that Jameson performed well enough that they called him up in September.
Jameson debuted for the D-backs on September 15th, firing seven scoreless innings in a 4-0 shutout win of the Padres. He made four starts, three of them classified as quality starts where he pitched at least six innings and allowed three earned runs or less. Due to his impressive sinker, Jameson induced a ground ball rate of 56.1% according to Statcast. The combination of an above-average swing-and-miss rate and heavy ground ball rate gives Jameson a very high ceiling as a starting pitcher.
The expected stats weren't as bullish about Jameson's actual run prevention skill, as his xERA was 4.49 due to the quality of contact allowed. 48.5% of the balls put into play against him had an exit velocity of 95 MPH or greater, although the high ground ball rate and the D-backs outstanding defense mitigated that. Given that he's only faced 98 big league hitters, there isn't much to read from in his expected stats.
Jameson will be one of potentially four pitchers vying for the final two rotation spots next spring. I think he has an inside track to a rotation spot, as he can maintain his best stuff longer than Ryne Nelson and has a better arsenal of pitches than Tommy Henry and Brandon Pfaadt. The D-backs should have a pretty solid idea if Jameson is better suited for the rotation or the bullpen by the end of the 2023 season, although I think he'll stick in the rotation.
Given his ability to maintain his top stuff for at least 75-80 pitches in a given start, all of the previous questions about Jameson's ability to hold up as a starter have been answered. A freak athlete who is also highly competitive, he is more likely to end up much closer to his ceiling of an ace compared to his floor of a multi-inning high leverage weapon in the back-end of the bullpen. Better refinement of his changeup and curveball will be key for him to reach that ceiling, but I feel like the worst possible outcome long term is he settles into a #3 starter (90 ERA-/110 ERA+, 170 IP).