The Catalan outfit face a huge task to qualify for the last-16 stage of the competition, as last week's 3-3 draw with Inter Milan has left them in third spot in Group C, three points behind the second-placed Italians.
Inter would join Bayern Munich in the next round if they beat Viktoria Plzen at home later this month, with Barcelona facing the prospect of playing Europa League football for a second successive season.
Xavi has insisted that Blaugrana are moving in the right direction, and he is confident of helping the club in their bid to return to their former glories.
"I still insist that we are on the right track. We have scored 20 goals in the league, conceded only one. We are better than we used to be. It is true that we have to improve in Europe, but that is the case with every newly started project," Xavi told reporters.
"We are playing better in the league. Tomorrow is going to be a tough match, and we have to work on winning it. I'm a Barcelona fan. I want the best for the club. If I feel I can no longer do anything, I will go home. But for now, that's fine. There is still a lot left in the season."
"The president also continues to be optimistic. He is always positive, and helps us. What happened against Inter was unfortunate, and in Munich and Milan as well. It should not have happened, but we have to go on our own way. We have not talked about my continuity," he added.
Barcelona will head to Bernabeu on Sunday looking to make it back-to-back wins over Real Madrid, having recorded a 4-0 victory when the two teams last met in March.
"I love playing versus Real Madrid. I'm a competitive player, and I always love to play matches like these," he added.
"Last season we reached El Clasico in a bad shape. Today, we reach El Clasico and we are the top of the league. El Clasico is three points. It's also an important match to get a morale boost. Our goal is to win the Clasico and to play the way we believe in. Pressure, attack with intensity."
Xavi also confirmed that Jules Kounde would be back on Sunday, with the central defender recovering from the hamstring injury that has sidelined him since the September international break.
"He is 100% ready, is training well, and will be ready for tomorrow's match," said the Barcelona boss.
Blaugrana will play another five games before the end of the month, facing Real Madrid, Villarreal, Athletic Bilbao and Valencia in the league, in addition to a home Champions League clash with Bayern. body check tags ::