High three-quarters arm slot; slow delivery; difficult to watch; stiff arm action; wrist wraps; upright finish; all arm and shoulder; lacks hip rotation; inconsistent finish; big, mature body; below-average athlete.
Fastball that is relatively straight; leaves it up often; overthrows to touch 94-95 mph; will show a two-seam (87-88 mph) at times; below-average command profile; misses arm side; plays darts; doesn't create extension to move the ball around.
Could also be termed a cutter; some have short action; others with a bit more sweep; gets on the side of the ball well; some late two-plane break that dives towards left-handed batters back foot; solid-average potential.
Inconsistent velocity; still finding a feel; some are soft and loopy; others that are hard in the low-80s; 12-6 action regardless of velocity range; best are in upper-70s, but couldn't command those.
Changeup is firm; gets on the side of the ball; lacks confidence; will overthrow; didn't sequence it; seemed forced.
Having seen Sappington last year, I can say he's taken steps back in his developmental path. The delivery has gotten worse, the secondary offerings are weaker, and the control profile is becoming bleak. In addition, the intangibles don't appear to be the same, as he doesn't have the same level of energy and competitive fire that he's had in the past.
Though Sappington currently starts, if he is going to make it to the major leagues it'll have to be as a middle reliever. Well built, and sporting the velocity to get second looks, Sappington's mechanics and lack of secondary offerings will keep him from succeeding at the highest levels as a starter, long term.