Pivetta won't start in Wednesday's doubleheader against the Nationals, Matt Breen of The Philadelphia Inquirer reports.
Two straight postponements to begin the series in Washington means Zach Eflin and Jake Arrieta will start in Wednesday's twin bill. The Phillies have yet to announce their extended rotation plans, but Pivetta figures to take the mound Thursday in the series finale or in Friday's series opener versus the Marlins.