8/7/18 - Ran fastball up to 91 in Area Code Games outing.

5/7/18 - Oklahoma commit. The first thing that stands out about Heller is his combination of size (6-foot-7) and athleticism. The big junior moves well on the bases and when playing first base and is also an accomplished high school hitter, launching multiple home runs well out of Tempe Diablo Stadium. While the delivery isn't as clean as some other draftable high school arms, Heller has consistently performed for Mesquite and showed off the type of stuff that makes him a strong follow between now and next June. His mostly straight fastball sat 87-89 mph, touching 90 and was consistently down in the zone from a very high arm slot. The slot is artificially raised to straight overhand due to his spine angle, creating a very low left shoulder through release. If this cleans up some it will make the whole delivery more athletic and fluid, also likely adding some life to his fastball when the slot drops. A lower slot would also fit well with his slightly across-body landing position, adding angle. Heller's best secondary offering was a fading 83 mph changeup he showed to left-handed hitters. The breaking ball was in the lower-70's with big break and could also be tightened up and thrown harder if the posture and slot are improved. Heller is already one of the top pitchers in the state regardless of class and the sky may be the limit with some mechanical alterations.