The Citizens will travel to Germany to face Borussia Monchengladbach on Wednesday and centre-back Mangala is confident of a positive result to get their knockout stage ambitions back on track.
"We still have games left to qualify, so we shouldn't sound the alarm yet," he said.
"We just have to show that Juventus was an off day, and keep on working on what we do well and get rid of what didn't go too well.
"We are still confident, and we will stay with the same dynamic we've had since the start of the season and we will even get stronger.
"We know we have the right squad to go a long way in the Champions League."