Inter only had one shot on goal in Florence as they lost 4-1.
"I think it's all too easy to read this match, aside from Fiorentina's merits," shrugged Stramaccioni.
"We played two games with more or less the same players, but I never imagined a game like this. I saw my Inter were really tired and struggling. I thought we'd pay a small price for the fatigue, but not to this degree. I evaluated the situation incorrectly.
"We could've done without this defeat, but I don't know how we can play so differently from Thursday to Sunday. Maybe I made a mistake. Inter were too ugly to be true."