Losing nearly 4MPH on his fastball since 2011 is big contibuter as well, it's basically just a really bad knuckleball now and it gets hammered. It was a nice pitch for him back with the Mets that he threw for strikes consistently, with the 8-10 MPH difference between his knuckler really f***ing with a batters timing. The Dickey decline is a continuing trend and picking up his option (12M) for next year is looking less likely especially if there is turnover in the front office.
Someone stated in another thread he would better suited in a Tim Wakefield type of role, I think he would thrive pitching every other day eating up innings when needed as this young staff endures its growing pains. Its a shame AA didn't address the SP depth to actually make this a viable option this season.