With the D-backs having provided Webster with a three-run lead before he even took the ball, Harkey wanted him to throw the ball down the middle and let the natural sinking movement on his pitches carry it to the corners.
Webster took the advice to heart and retired the next 14 hitters he faced as the D-backs beat the Giants for the second straight day.
"Just told him to use his sinker more in the middle of the plate, because starting it on the black, it's never a strike, so hitters won't swing at it," Harkey said.