He said: "There are some moments where some teams like Bayern and Borussia play very well and play fantastic football and maybe next year they will not play like that in the crucial moment.
"I don't think that Real are worse than Borussia but Borussia deserved to win.
"It's one game. It's not one season. Why can't we beat Bayern or Borussia next season? Last season Dortmund went out in the Champions League group stage."