Oh, I guess this should go here too:
I think you have to cut bait on all three of them. Peterson is 30 and he isn't going to get better, and his $8M is not such a salary hit that it kills you. Manaea's $19mx2 is worse, admittedly, but he's shot. Senga's at $14M this year and next.
Call up Tong and let him learn on the job like Benge. The rotation becomes Peralta/McLean/Holmes/Tong and Scott, I guess? Edwards is a starter too, but he's 34 and not a future piece. You could use Myers as a #5 if you want Tong or Scott to simmer in Syracuse, but I see no reason to do that at this point.