Keller is scheduled to start Monday in the Royals' Cactus League game against the Padres, Lynn Worthy of The Kansas City Star reports.
While he makes his first start of the spring, Keller is expected to unveil a curveball, a new pitch he added to his arsenal during the offseason, per Alec Lewis of The Athletic. Keller is hopeful that the addition of the curveball as a fourth pitch will give him more time to further hone his changeup in side sessions while providing him with another alternative for hitters who handle sliders better than curves. Though he'll essentially be trading out the changeup for the curveball, Keller is still expected to rely heavily on the four-seamer/slider/sinker combination that accounted for 98.6 percent of his overall pitches in 2019.