The Phillies informed Kerkering following Saturday's game that he will be optioned to Triple-A Lehigh Valley, Todd Zolecki of MLB.com reports.
Kerkering was told bluntly that the team can no longer pitch him with so much on the line and just seven games remaining in the regular season. The right-hander gave up four runs over one inning in Saturday's loss, bringing his ERA to 4.97 over 58 frames for the year. His ERA is now over 9.00 since the All-Star break.