Stephen Strasburg will not make his scheduled start Sunday after an upper-back injury, which caused him to miss his last start, flared up.

The Washington Nationals will start Tanner Roark in the series finale against the Milwaukee Brewers.

Strasburg felt pain in his back during a warm-up session before Saturday's game. Dusty Baker said Strasburg is day-to-day.

The right-hander is 10-0 with a 2.90 ERA in 14 starts this season.