Brad Keller is two seasons removed from his days as a starter, and his bullpen transformation has come with the upsides that teams usually hope for: a velocity uptick (though his was more dramatic than is normal), higher whiff rate, more strikeouts, better production.
You don’t have to squint, though, to see remnants of who Keller was as a starter. After all, he still pitches a lot like one.
Keller is a rare five-pitch reliever, and none of his offerings are footnotes in his arsenal. He throws his four-seam fastball, which jumped a remarkable 3.4 mph last season alone, over 42% of the time, but the remaining approximately 58% is a fairly even split between his slider, sweeper, sinker and changeup.