Xavi has criticised Mourinho's side for their manipulation of the Bernabeu pitch both last Wednesday and prior to the league game which kicked off this unique series of Clasico clashes on April 16.
Madrid deliberately let the grass grow long and opted to keep the pitch dry for those matches in order to stifle Barca's slick passing game, a tactic which has angered Xavi.
"I believe people like to see attractive football on a good playing surface, not long grass and hard pitches," he said.
"It's deplorable that there are no regulations in place for the state of the pitches.
"In 2011, there are still no regulations and that's regrettable."
Despite his reservations about the Bernabeu pitch, Xavi hopes the talk will soon return to the football following the off-field controversies of the last week.
"I have the feeling that we are talking very little about football and that makes me sad," he said.
"I love playing against Real Madrid and I love playing in these big games. They are very exciting challenges. It's satisfying to be in the semi-finals and a reason to be proud."