Alonso said it was "the right moment" to announce the exit, but did not confirm his next post, saying it was "not the right moment to talk too much about the future".

Spanish and German media reported Friday the 43-year-old has already agreed to join Real and will link up with the Spanish giants after the Club World Cup, replacing Carlo Ancelotti, with a compensation payment of around 12 million euros ($13.5 million) to be paid to Leverkusen.

Taking over in October 2022, Alonso guided Leverkusen to an unbeaten league and cup double in 2023-24, the first Bundesliga title in the club's history.

In March 2024, Alonso declared he would stay with the club despite reported interest from Liverpool, Real and Bayern Munich, all of whom he represented as a player.

Alonso will be in the home dugout for the final time on Sunday against Borussia Dortmund, before his last match as Leverkusen coach away at Mainz.

"We have to enjoy this moment, with mixed emotions. I spoke this morning to the players, the staff, who have been with me during this unbelievable, fantastic three years," Alonso said.

"And now it’s the moment to share it on Sunday, especially with the fans, in the stadium on Sunday, where I lived great emotions and where I have become what I am right now.

"Football is about the moment and I think is a good moment for everyone. Let's enjoy it until the last moment. We can be happy and proud of what we have achieved always with the good feeling we're taking the club in the right direction."

Leverkusen's title defence ended with their 2-2 draw at Freiburg on Sunday, which confirmed Bayern as this season's title winners. Alonso's side will finish in second spot regardless of results in their final two matches.

- League and Cup double -

Alonso joined in October 2022 with Leverkusen hovering dangerously close to the relegation spots. The Basque immediately put the club back on track; by the end of the season, Leverkusen had risen to fifth, while making the Europa League semi-finals.

After bringing in several key pieces in the off-season including midfielder Granit Xhaka, striker Victor Boniface and full-back Alex Grimaldo, Alonso piloted Leverkusen to an unbeaten league and cup double -- the first in German football history.

In bringing Leverkusen their first league title, Alonso helped shatter the unwanted 'Neverkusen' moniker given to the club after five second-place finishes, three German Cup final losses and defeat in the 2002 Champions League final.

In 2024-25, Leverkusen pushed Bayern until last weekend in the league and remain on track for their second-best points total.

Alonso's men were eliminated from the German Cup semi-final by third-tier Arminia Bielefeld and by Bayern in the last 16 of the Champions League.