The defending champions were hammered 3-0 at Fiorentina on Thursday evening.
Capello declared in his column in La Gazzetta dello Sport: "Fiorentina wins, Inter loses and... Napoli smiles. The Nerazzurri's surprising nosedive in Florence confirms Antonio Conte alone at the top of the Serie A standings with a three-point advantage. A small gap, but still important, because now he hands the future of the Scudetto into the hands of Napoli, a team that has no other commitments or objectives beyond the race for the tricolor.
"I didn't like the Inter team I saw at the Franchi, beyond the clear defeat. In over 70 minutes they were unable to understand how to attack Fiorentina's defense, so much so that they had very few clear chances. A bit like what happened in the first 70 minutes against Milan in the derby. At the moment Inzaghi's team is not brilliant, they are unable to play on the wings like they did until recently and are slow and predictable in the development of the maneuver. Above all, they lack rhythm."
Capello continued: "With the Viola staying low, while attacking the ball holder with a ferocious pressing, I would have expected more ball movement, more changes of play to move the opponents. And instead Calhanoglu - the man who has the footballing qualities to give speed to the changes of front - struggled a lot.
"On more than one occasion you could see Bastoni calling for the ball in vain on the left side, continuously waving his arms, while the action developed (badly) on the opposite side. So Inter's danger was reduced to set pieces and corners, but you can't always hope to resolve the games from set pieces, when you are in difficulty at the level of play."