Real Madrid midfielder Xabi Alonso has admitted that it will be difficult for his side to retain the Champions League title this season.

Madrid goalkeeper Iker Casillas has claimed that Los Blancos are confident of retaining the European Cup, but no team in the modern era has won back-to-back Champions League titles.

"For years we fought for our 10th title. Now the aim is to defend our title, and if nobody has managed to do so, there's a reason. We're going for it," Alonso told reporters at the unveiling of Madrid's new Champions League kit.

Madrid beat rivals Atletico Madrid in last season's final in Lisbon.