Adam Kolarek made the Rays opening day roster this season as the last man into the bullpen. As I’ve written before, I don’t know if Kolarek is good, but I do think he’s interesting.
To sum up the more detailed preview, Kolarek has a strange assortment of pitches that he’s used to dominate the minor leagues, but it’s not certain that they’ll translate to success in the majors.
He throws from a low arm slot. His best pitches are a sinker and a changeup, both of which have large amounts of armside run. He throws a slider, as most left-handed relievers with a low arm slot do, but it’s not actually that much of a wipeout pitch, lacking extreme gloveside run.