PHILADELPHIA -- The Washington Nationals are pushing back Max Scherzer's next start because the ace right-hander is dealing with back soreness.

Manager Dave Martinez says an MRI on Scherzer's back came back negative, and the three-time Cy Young Award winner threw from 75 feet on Friday. Scherzer experienced soreness in his middle back after his last start.

Anibal Sanchez will start in his place on Sunday against the Phillies in the final game of a three-game series.

Scherzer was 7-0 with a 0.84 ERA in his last nine starts before the All-Star break.