The thing is, he was often low 90s in the minors (as a starter, admittedly) before his uptick at the alternate site in 2020. It’s not shocking his stuff regressed again, even if he’s relieving.
Interesting that Fangraphs has acknowledged the slowness of some of their prospect lists by splitting them in half like this. I personally like getting it piecemeal like this because, as Eric acknowledges, some of this info will be out-of-date when they get the whole list ready by the summer.