Borussia Dortmund manager Jurgen Klopp has claimed that his players are beginning to feel the effects of a long season after reaching the DFB-Pokal final.
Goals from Henrikh Mkhitaryan and Robert Lewandowski earned Dortmund a 2-0 victory over Wolfsburg on Tuesday night, but Klopp admitted that his team were not at their best.
"We have made the final, all is well," the German told reporters.
"With the quality that Wolfsburg have it is normal they have chances. The boys have played a lot of football and today it has taken its toll for the first time.
"Wolfsburg always stayed focused and we had our chances on the break, but we didn't have our usual control because of a lack of freshness."
Dortmund will face either Bayern Munich or FC Kaiserslautern in the final of the competition.