Freddy has been a very good, reliable pitcher for several years. That said, he will almost certainly regress over the next few years. Plus, I find it difficult to believe that starting pitchers can stay healthy for so many years in a row.
Even if we assume Peralta will continue being five wins above replacement level, we have so many pitchers making near league minimum that can likely be two or three wins above replacement level that it doesn’t make sense to spend over 20% of our payroll on an aging starting pitcher.
Especially since he Is not an ace. 🙂