Chelsea face crucial matches in the Barclays Premier League prior to the trip to Basle in the Europa League semi-finals, beginning with Wednesday's west London derby at Fulham, as they seek to secure a top-four spot and a return to the Champions League they won last May in Munich.
"It's not difficult (to overcome)," the Brazil defender said. "You need to take positive things. For us it was a great game. In the second half we controlled the game, we controlled one big team and created a lot of opportunities. In the future we have confidence. I'm always positive."
He added: "We have important games in the future. We need to win. We need to be in the best position in the league and win the Europa League."
Chelsea's defeat came at the end of a run of six matches in 16 days and following Thursday night's Europa League quarter-final second leg with Rubin Kazan in Moscow.
But interim boss Rafael Benitez played down the impact of fatigue, citing the second-half response.
"It's more that City were very strong in the first half," he said.
"We know physically players like Yaya Toure can make a big difference in the middle of the park and also (Sergio) Aguero. They have very good players.
"The first half we didn't show the level that we wanted to show and second half the reaction of the team was quite positive.
"For me the positive thing is we saw in the second half we could do much better."