Thomas Mueller admitted Bayern Munich’s treble dreams received a reality check at the hands of Real Madrid in the Champions League. Bayern left themselves with everything to do in the second leg in Madrid on Tuesday after losing the semifinal first leg 2-1 at the Allianz Arena. Bayern have only rarely being tested by their domestic rivals this season, and Mueller said that may have been part of the problem on Wednesday night. “We were too naive, we had several very, very good chances. In the Bundesliga, we say ‘thank you’,” said Bayern’s captain, who squandered several opportunities himself against the Spanish giants. “Perhaps the importance of the game played a role.” Bayern wrapped up a sixth straight Bundesliga title three weeks ago and reached the German Cup final on May 19. Yet an off-key Real managed to all but burst Bayern’s treble dreams. “I have rarely seen a Madrid team who allowed so many chances, that’s why we won’t give up,” said Bayern coach Jupp Heynckes. Real inched closer to a third straight Champions League final after Marco Asensio’s winner capped their comeback win, yet Madrid were below-par by their own admission. “Bayern were perhaps the better team, that was an average performance from us, it must be said,” conceded Real’s Toni Kroos, a former Bayern midfielder. Nevertheless, Mueller is optimistic for the return leg. “We won there last season,” said the Germany international of the quarterfinal away leg last year. In 2017 in Madrid, Bayern led 2-1 after 90 minutes to force extra time, but then conceded three goals, as Cristiano Ronaldo wrapped up his hat-trick, to lose 4-2 and bow out. “Real are definitely vulnerable. We need a different killer’s mentality,” added Mueller. To compound Bayern’s problems, Arjen Robben, Javi Martinez and Jerome Boateng all picked up injuries. Boateng is out for the rest of the season with a groin injury, Bayern confirmed on Thursday. Robben, who has a groin strain, and Martinez, who has a head injury, are doubtful for the return leg.