The veteran midfielder admits they've thrown away their lead at the top of the table.
Gattuso said: “It's a fact. We could have gone seven points clear and instead find ourselves with a two-point lead before the derby. It's been 10 days since things started going in the wrong direction.
“If the title race is open again, it's our fault, but destiny is in our hands. The derby will be decisive. We must prepare for it well both in the head and in the legs.
“I expected more from the entire team. And it angers me that in Palermo every time we put a ball in the box there was no one ready to put it in the back of the net.
“If Mathieu Flamini and I were the most dangerous players, there is something not right.”