Brad Keller worked out with Driveline this offseason and has added a curveball to his arsenal:
To help the curveball, Keller added sweeping action to his slider to have two different movements on his two breaking pitches. His slider is still his best secondary pitch as a swing-and-miss option. The curveball is useful to throw hitters’ timing off — in a live session last week, Vinnie Pasquantino grounded out to second, thrown off balance by the spin. Over time, Keller hopes the curveball can evolve to a swing-and-miss pitch.
“I can really see some guys hesitate before they swing,” Keller said.