Interesting prospect list by one website, dated 1/5/23. After Mayer-Casas-Rafaela, they have #4 Niko Kavadas, #5 Yorke, #6 Matthew Lugo, and #7 Bleis.
It's a fantasy site, so Niko's .437 OBP is big... also, noted is Lugo's rise after shifting full-time to third base (he's 21, so there's still time to move him to another position, unless he can wait until he's 32 and Raffy's gone).
https://www.pitcherlist.com/boston-red-sox-top-fantasy-baseball-prospects-2023/