Niko Kovac said Bayern Munich's midweek exploits in the DFB-Pokal took their toll during Saturday's 3-1 win over Schalke and suggested the cup could be to blame for Bundesliga leaders Borussia Dortmund dropping points earlier in the day.
Goals from Robert Lewandowski and Serge Gnabry followed a Jeffrey Bruma own-goal and an Ahmed Kutucu equaliser to ensure Bayern bounced back from a 3-1 defeat to Bayer Leverkusen with a victory at Allianz Arena on Saturday.
The win came after an extra-time victory over Hertha Berlin four days earlier and it saw Bayern narrow the gap at the top of the Bundesliga to five points.
Dortmund let slip a three-goal lead in the final 15 minutes of their 3-3 draw with Hoffenheim, and Kovac pointed to the leaders' penalty shoot-out defeat to Werder Bremen as a possible cause of their collapse.
"We did a really good job in the first half and temporarily in the second," head coach Kovac told reporters.
"But the 120-minute cup match was noticeable, in Dortmund too. You must not allow that when you're three up after 75 minutes.
"That was a warning, but I think it was a deserved win and the right margin of victory."