His agent did really well. Minor league deal for 2018, minor league deal for 2019, no appreciable skill change to this point but they were able to leverage some luck and ERA results (and postseason results) into $11M.
Actually for 2017 he had signed an identical 2/$11M deal that was obviously dead-money by the end of the year. Pitt dumped him off to Tampa who cut him in March 2018. This one might turn out the same!