AC Milan coach Sergio Conceicao admitted he was concerned after his side lost 2-0 to Juventus in Serie A on Saturday, their first defeat since he took charge of the team last month.
Conceicao's reign began with a 2-1 win over Juventus in the Italian Super Cup semifinals but goals from Samuel Mbangula and Tim Weah condemned Milan to a league defeat by Thiago Motta's side.
"I am the coach and I have to change things. I am responsible for this defeat and I will work to find a solution to avoid such moments in the future. It's a possible mission," Conceicao told a press conference.
"The first step to winning the game is to want to win it... I am the guilty party and I take responsibility, but everyone has to examine their conscience."
With a Champions League tie against Girona on the horizon, Conceicao said he was worried about his players.
"I'm thinking about what I can do to change the atmosphere in the dressing room and around the team. We have to do more because we have the league, the Champions League and the Italian Cup," he said.
"We must improve, reflect on our current situation and consider changes in the dressing room environment."
Milan are eighth in the standings, six points behind fourth-placed Juventus.