my son is similar in size and hit 90 this Fall. While Most pitchers r bigger guys it's not always the case. Does he want to pitch in HS and beyond? If he goes to a showcase he will get a velocity number. It's only part of pitching but a big one. The number gets their attention, but he has to have more than that-location, and good offspeed pitches. What it comes down to is not the size of the pitcher but how the ball comes across the plate.