Carlo Ancelotti says Real Madrid must play with greater intensity if they are to keep their hopes of a record-extending 15th European title alive, with their Champions League semi-final tie against Bayern Munich in the balance ahead of Wednesday's second leg.

Madrid were crowned champions of LaLiga with four matches to spare on Saturday, beating Cadiz 3-0 before watching their closest rivals Barcelona slip to a 4-2 defeat against Girona.

However, that success has not stopped Ancelotti from being critical of Madrid's performance in last week's first leg against Bayern, a 2-2 draw at the Allianz Arena.

He has warned his players that they cannot afford another subpar performance if they want to contest the final at Wembley Stadium on June 1.

"We need a match with intensity, with pace... Looking at the first leg, defensively we could have done a lot more," Ancelotti said at Tuesday's pre-match press conference.

Bayer Leverkusen ended Bayern's 11-year Bundesliga reign by securing the league crown last month, but Ancelotti says that will only boost Bayern's motivation as they chase a seventh European title.

"We are similar clubs because they have a great history and a lot of success," Ancelotti said. "We have to respect our opponents because they did very well and were better than us in the first leg.

"We are very excited because it could be another magical night for us, but there is no optimism. We are aware of the difficulties that we are going to face."

Defender Dani Carvajal, who has already lifted the Champions League trophy five times with Los Blancos, believes the squad are brimming with confidence after going unbeaten through their last 42 games (excluding extra time).

He joked Ancelotti was "getting more and more fearful" each season but praised his coach's role in keeping the players focused on the task at hand. 

"There is euphoria because we are having a great year," Carvajal said.

"We are all very excited about the European Cup. We know it in the dressing room. In the street the fans congratulate us and give us a lot of encouragement to dream of winning it again.

"We are two games away from winning the Champions League. Ancelotti has kept our eyes open and we have all added up. That's what counts for us to achieve our objectives."