Roupp and the Giants won't face Atlanta on Thursday, as the game was postponed due to inclement weather.
Thursday's game will be pushed back to Aug. 31; meanwhile, Roupp's next start is likely to come Friday during San Francisco's series opener in Miami. The 27-year-old has struggled since the beginning of June, giving up four or more runs in two of his three starts this month while failing to make it through the fifth inning on both occasions.