The LaLiga leader progressed after a hard-fought 3-2 win against Barcelona on Thursday (AEDT), with substitute Federico Valverde hitting an extra-time winner.

Athletic overcame Atletico Madrid 2-1 in the other semi-final on Friday (AEDT), and Ancelotti has admitted he will have to change his tactics for Marcelino's men.

"I'm extremely happy to be experiencing this period, I'm very excited," he told reporters in a news conference. 

"Being back in a final again is special and even more so when it's at the helm of Real Madrid. This team is used to these types of games and these moments."

The two teams played each other twice in December in LaLiga, with Madrid emerging victorious on both occasions, 1-0 at the Bernabeu and 2-1 at San Mames.

"We have to analyse the opposition," Ancelotti added. "We know each other very well because we have played twice in a month, once in Madrid and once in Bilbao. It's going to be a very hard-fought match, just like the others were.

"Athletic have a range of attributes, including a solid defence, organisation, pace up top, quality on set pieces... We have to bear that in mind. Our approach will be different to the semi-final because Athletic have different characteristics to Barcelona."

The former Chelsea and Everton manager also addressed a question about his team's style of play and he was keen to dismiss the idea that there is a defined approach that guarantees success.

"I respect everyone, every facet of football is to be respected," he added. "There's not some magic approach which guarantees you'll win. The perfect system doesn't exist.

"You don't win every time because you play with the ball, or on the counter. A game can be won on set-pieces too. If we play defensively one day, it doesn't mean we're a defensive team. We've scored more goals than any other team in LaLiga."

Ancelotti also had words of praise for Karim Benzema, who scored Madrid's second against Barcelona and has plundered 23 goals in 26 appearances in all competitions this season, as well as registering nine assists.

"He hasn't changed, he's as humble as ever," his manager said. 

"What's changed is how others are seeing him. They're looking to him more as a leader. I think people look at him differently to how they did six years ago."