Spencer Giesting
Spencer Giesting was an 11th-round pick by the D-Backs in 2022 but was an over-slot signee. Giesting inked a signing bonus worth $350K and is coming off a solid 2023 season. The left-hander is only entering his age-22 season and will likely start the year at Double-A Amarillo. If he makes a step forward, then you might see him move up in prospect rankings.
Giesting owned a solid 4.00 ERA, 4.58 FIP, and 1.46 WHIP in 117 innings at High-A Hillsboro. Giesting’s 23.8% K-rate was slightly worse than league average. But he had a quality 0.69 HR/9 rate with a 45.8% GB%. But he struggled to limit walks with a 13.6% walk rate. That was much worse than the league average rate of 10.1%.
In his defense, this was his first extended look against pro players, and he made improvements during the year's second half. After the All-Star break, Giesting cut his BB% down to 10.2% while keeping a 23.9% K-rate and 0.89 HR/9. Overall, the lefty had a much better-looking bottom line with a 3.86 ERA, 4.36 FIP, and 1.20 WHIP.
Giesting does not throw hard, averaging out in the low-90s. But he throws a plus slider. He’ll also mix a change-up into his arsenal, but it’s a clear third pitch. His mechanics can get in the way of his command, but as I stated earlier, he got better at limiting walks in the second half, and this was the first time he faced pro batters regularly.
Double-A will be the real challenge for Giesting. If he can continue to make the improvements he made in the second half of last year, he could eventually put himself into the Diamondbacks’ long-term plans. At the very least, he could find himself as a solid lefty hybrid reliever/starter in the near future.