"It will be a very difficult game, Manchester United are one of the best teams in Europe today and they're showing it every game," Xavi told a news conference.
Barca have been using several mechanisms to increase their revenue in order to offset losses, reduce debt and fulfil LaLiga's financial fair play rules.
Barca, in second, are eight points clear of Betis, in fifth, and if they can extend that gap to 11 with three games left to play, their spot in the Champions League will be secure.
While Barca were expecting huge backing at the stadium ESPN reported there were close to 30,000 Eintracht fans among the 79,468 crowd.
The Clasico on Sunday will likely have very little bearing on the current season for either Barcelona or Real Madrid -- but it should set the tone for the next one.
Xavi Hernandez certainly benefited from those reduced expectations during the first few weeks of his tenure.
The Gabon international moved to Barcelona on a free transfer last month after terminating his contract with English Premier League club Arsenal..
The Catalans crashed out of the Champions League in the group stage with just two goals scored in six matches.
Barcelona manager Xavi Hernandez said that he had not seen the incident, but apologised for Araujo's actions.
Dembele has been left out of Xavi Hernandez's squad to face Athletic Bilbao in the Copa del Rey last 16 on Thursday night.
The deal comes despite severe financial difficulties at the club.
Barcelona crashed out of the Champions League following a 3-0 defeat at Bayern Munich on Wednesday, failing to make it past the group stage of the competition.
Xavi Hernandez said former team mate Lionel Messi deserved his Ballon d'Or win, describing the Argentine's record-extending seventh victory as "total justice".
Depay calmly went around goalkeeper Geronimo Rulli to score a dramatic 88th-minute goal that restored their lead.
New manager Xavi Hernandez will take charge of the team in the Catalonia derby against Espanyol on Saturday.
The former Barcelona captain has always been a strong candidate for the job but he rejected to fill the position at Barcelona twice.
Font believes luring former midfield great Xavi Hernandez back to the club would spark another golden age for the Catalans.
The former captain was offered the position last January following the departure of Ernesto Valverdeز
Xavi Hernandez has reiterated his desire to coach Barcelona in the future but suggests he will not return until a different board brings a new sense of direction to the club.
Barcelona wanted to follow the same manner of 2009 when the board gave the chance to Pep Guardiola, who led the club to win six titles in the first season.