Xavi: Clasico mud-slinging is sad
UEFA investigated both clubs after the ill-tempered game at the Bernabeu, which Barca won 2-0, and the arch rivals each filed complaints about the other with European football's governing body which were rejected on Monday.
"From my point of view everything that has been happening is sad," Xavi told a news conference ahead of Tuesday's second leg at the Nou Camp.
"It would be nice to talk about football instead and not these ridiculous issues," the Spanish World Cup winner added.
"We will try not to let any of this tension affect us, which is negative for football and sport in general. It's impossible but we will try."
Barca were furious with Real coach Jose Mourinho, an assistant at the Catalan club in the late 1990s, for comments they felt belittled the achievements of his counterpart Pep Guardiola.
Real also accused some of the Barca players of diving and play-acting.
Portuguese Mourinho was sent from the bench in the second half for protesting against the dismissal of compatriot Pepe, who is suspended for Tuesday's game and will watch from the stands with his manager.
Barca and Real provided the majority of the players who won the World Cup in South Africa last year but there were ugly scenes when the two teams met in last month's La Liga game, the King's Cup final and the Champions League first leg match.
Xavi said the incidents would not affect the atmosphere the next time the European and world champions met up for international duty.
"There won't be any problems with the national team. Everyone is very professional," he said. "We won Euro 2008 and the World Cup together and, what's more, in a fantastic atmosphere.
"It's logical there is tension as we have played many games in a short space of time which has never happened before."
English Premier League leaders Manchester United will defend a 2-0 lead over Schalke 04 when they host the Bundesliga side in Wednesday's other semi.
The final will take place at London's Wembley Stadium on May 28.