Background: Rayner Castillo was signed out of the Dominican Republic in January 2021 at the age of 16. After three seasons between the Dominican Summer League and Florida Complex League, Castillo has spent his first full season after coming off the IL in Lakeland in 2024. He just turned 20 back in June.
Physical description: Listed at 6’3, 180 lbs, Castillo has certainly increased his size with wider shoulders and big tree trunk legs. Castillo works from the first side of the rubber with a mid 3/4 arm angle as he pitches from the stretch. He throws a four-seam fastball, sinker, slider, and a changeup. For his age, he has very good command of the strike zone.
Fastball: 50
Sits at 94-96 that tails with natural sinking action. Can set up the pitch on the top of the zone to gain some swings and misses when he mixes it with his changeup. Gets a lot of ground balls with the pitch and can pitch to both sides of the plate.
Sinker: 50
It is his best pitch. Bowling ball heaviness to it, hitters have a hard time getting elevation on the pitch. Good, late, downward movement on the pitch. Attacks the low part of the strike zone for strikes.
Slider: 45
When Castillo throws the pitch with consistency, it is a good pitch with nasty, late breaking action. Throws it with good velocity, it is a pitch he has been throwing more to finish off hitters. Looks more comfortable throwing it against lefties versus righties at this point. It can sometimes lack depth.
Changeup: 40
Good, fading action with the pitch, shows good, late fade action and depth. Needs to throw it with more separation to his fastball as it is currently sitting only at 88-90 in order to become a better pitch.
Overall:
Rayner Castillo is one of the top pitching prospects in the Detroit Tigers’ system. The organization has been focusing on refining his slider, and the work appears to be paying off. If Castillo continues to develop, he has the potential to emerge as a Top 100 prospect.
His fastball currently sits between 94-96 mph, and with further improvement to his changeup, particularly to better neutralize right-handed hitters, Castillo has a solid chance to remain a starter. As he builds up his arm strength and innings, his stock as a promising pitcher continues to rise.
Chris Brown