(CNN) -- Real Madrid manager Jose Mourinho has rejected claims of dressing room unrest as the club prepare to face rivals Barcelona in Wednesday's second leg of their Spanish Cup quarterfinal tie.
The press in Spain claim relations between the Portuguese coach and some of his Spanish players have been strained in the wake of their 2-1 defeat in the first leg of their "El Clasico" clash last week.
Mourinho was booed by a section of Real Madrid's fans during the 4-1 defeat of Athletic Bilbao in La Liga on Sunday, despite the team maintaining a five-point lead over Barca at the summit, and newspaper reports on Tuesday claimed he was going to leave his post in June.
The former Chelsea and Inter coach was terse when questioned about the claims at a press conference, while the two players at the center of the speculation came out to back their manager.
"At the moment, we're leaders with a five-point lead on the team everyone says are the best in the world," Mourinho told reporters, in quotes carried by AFP.
"Before I arrived here, the club was used to being knocked out of the Spanish Cup by teams from a lower division, and we won the competition last season.
"And then we won six games out of six in the Champions League. So I think we haven't got as many problems as people want to say."
Mourinho's side have lost three of the four matches they have played against Barcelona this season, and his tactics were criticized in the wake of last week's 2-1 reverse at their own Bernabeu Stadium.
But the two players Mourinho is said to have fallen out with -- Spain's World Cup-winning goalkeeper Iker Casillas and defender Sergio Ramos -- backed their manager on Real's official website.
"Our relationship with the coach has always been good," Ramos said. "Mourinho is the ideal coach for this club and we're happy to learn from him.
"He is very experienced -- he's won it all and is really bringing out the best in us so that each of us plays his best."
Real captain Casillas added: "I think I haven't seen such a great atmosphere on the team for a very long time. The atmosphere on the team is pleasant and excellent. Spirits are high. There is no reason to worry."
Meanwhile, in the Spanish Cup quarterfinal played on Tuesday, third division Mirandes stunned Espanyol, who play in Spain's top flight, to go through to the last four.
With Espanyol leading 3-2 after the first leg, Rui Fonte's goal seemed to kill off any chances of a shock but late goals from Pablo Infante and Cesar leveled the tie up at 4-4 on aggregate, sending lowly Mirandes through on away goals.
In Italy, Juventus booked an Italian Cup semifinal with either Lazio or Milan after a convincing 3-0 win over AS Roma.
Emanuele Giaccherini grabbed the first after just six minutes after being put through on goal before Juve legend Alessandro Del Piero made it two with a trademark strike, cutting inside and finding the top corner.
Erik Lamela was sent off for Juve but that didn't stop Fabio Quagliarella from making it 3-0 late on.