Milan go to Spain next week with a 2-0 aggregate advantage.
"We know it is complicated by the result of the first leg, but we can turn it around. As they won, so can we. We are confident that we can overcome this," he told ESPN.
"This may be the game that we rise again. I know there are many people who are waiting for us to lose so as to say that this is the end of the Barcelona cycle, as it happened last year when there were results that were not good.
"The team is a little off after recent negative results, we have come unstuck for the details. We know there are things that we have not been doing well.
"We like to have the ball and leave plenty of space on the counter-attack. We lost to Milan and Madrid, who have players who are very fast on the counter. We need to slow things down.
"Now is the time to stand up and be ourselves again. Barca is this, when we lose two games everything falls down and when we win, it's normal.
"We always have to win here. We know that and we have no problem."