The Phillies optioned Falter to Triple-A Lehigh Valley following Wednesday's 3-1 win over Atlanta.
Though he struck out eight in a quality start in his last trip to the mound July 29 in Pittsburgh, Falter was sent back to the minors after the Phillies no longer had room for him in the rotation following the acquisition of Noah Syndergaard from the Angels on Tuesday. Syndergaard is slated to start Thursday's series opener with the Nationals and will fill the opening on the 26-man active roster vacated by Falter.