Out of the strong Kansas prep class this year, Duensing fared quite well this year in Arizona rookie ball; he only made eight appearances and four as a starter, but he put up a 1.38 ERA with a 7.62 K/9 and a 3.46 BB/9, relying mainly on a fastball-changeup combination. His curveball is still in its infancy, but again, keep in mind that he’s only 18 years old and far away from the majors.
Clocking in at 6-foot 4 and 175 pounds, the broad-shouldered Duensing is an extremely projectable athlete. Adding muscle to his rather-skinny frame will provide a lift to both velocity and stamina, allowing him to pitch deeper into and maintain his stuff in games. As you can see here, Duensing has a free-and-easy delivery which equates to clean mechanics and less arm stress. Because of his loose arm, he works quickly which is a positive.
This season, his fastball was sitting around 89-91 mph with some movement, at times touching 92-93. Compared to sitting in the high-80s for most of the high-school season, and you can see how Duensing could become something a lot better than he is now. His changeup is thrown often but doesn’t have the velocity separation that makes it effective, and his curveball has an 11-to-5 late break to it. Because he will fill out his frame, I’ve given Duensing a lot of projection.
Overall, this is a project arm that will test player development. He has raw tools but he has major work to do with command and his secondary pitches. Because he’s so far away from the bigs, Duensing carries high risk but simultaneously has the upside to be a #3/4 starter in the majors, but he — and the player development staff — is going to have to put it in the work for him to get there.