Castellani, a 2014 second-rounder, is a young, durable, and projectable starter with a projectable three-pitch mix. He works from a full-windup and has a herky-jerky delivery, with a long arm action and a wrap in the back. The arm action reminded me of Brent Honeywell (RHP, Rays). Even with the moving parts, he repeats the actions well, and throws strikes with above-average control this year (2.55 BB/9 over 137 1/3 innings, after 2.7 BB/9 over a league-leading 167 2/3 innings last year in the Cal League). He throws both a two-seam and a four-seamer around 90-to-93 mph, with run and tail on the four-seamer and plus sinking action on the two-seamer to generate a good deal of ground ball outs (career 1.31 GO:AO ratio). He throws strikes with the fastball with above-average command, setting up an average slider in the 84-to-86 mph range that shows average tilt and depth, though he’ll need to develop more consistent feel for the pitch. He shows good arm speed and arm action to sell the changeup well in the 84-to-86 mph range, with late fade. He’s got pitchability, and he’s showing big-time durability by already nearing 500 career innings in the minors at such as young age – the three-pitch mix and quality of the stuff should net him a big league rotation spot as a solid number four starter.