Will defer to others who can recall. I thought he was up to 90-91 mph max last year. If he can get to 92, with that poise, command, spin and off speed stuff he can play in upper levels for sure.
EDIT: I reviewed BA prospect report on M. Rodriguez, and to paraphrase (info for subscribers) is that he pitches 88-90 and max was 92, which is what I recalled, but has high spin, and has slider, cutter and change up, with the slider being a very good pitch. And you will get the same info from the post game report for 4/4: https://creators.spotify.com/pod/profile/timberrattlersreview/episodes/Manuel-Rodriguez-Announces-His-Presence-With-Authority-e314mki
So IF he can get his velo up a few ticks (think 92-93 with a max of 95) then you have a solid mid to back of rotation pitcher. But that's a lot of IF in that sentence. He is 19 years old by the way, in high A.
EDIT#2: OK, as I'm reading these reports again, it makes me feel so old that when I see a lot of the Brewers pitchers with fastball velo of 91-95 as average or below average, boy I remember the late 90s and early 00s when our pitchers (not named Sheets) were all 89-91, and those who hit 95+ were high end. Now its 95 average, and 98+ as high end.