Pioli's side have failed to win in their last five games in all competitions and recently suffered a humiliating loss in the Italian Super Cup final and were knocked out of the Coppa Italia.
"I know my players well, if they made many mistakes, I’m the first one responsible. I've tried to be clearer, simple and direct to work better," he told reporters on Saturday.
"We have the resources to overcome this period... we are recovering injured players, and we are happy like this."
Milan will host Sassuolo on Sunday, hoping to end their winless run against a side hovering one place above the relegation zone.
"Even a dirty but characterful victory would do us good. We have to be a self-aware and solid team. We are happy to be playing at home again. Sassuolo are fast and technical, aggressive at times," Pioli said.
"The better you play the more chance you have of winning, but above all we need positive results now to regain enthusiasm, talking is of little use."
Pioli defended Romanian goalkeeper Ciprian Tatarusanu and added that new signing Denis Vasquez (24) was not ready for the team yet.
"We're conceding too many opportunities and it becomes difficult also for the goalkeeper. We must defend better as a team," Pioli said.
Pioli said he had not decided yet on Ante Rebic (29) and Theo Hernandez (25) despite both being back in training and gave updates on others.
"Theo was OK yesterday, if he continues like this today, he will be available tomorrow. (Davide) Calabria picked up a knock, but he trained with the team, and he's OK. Fikayo (Tomori) won’t be there."
