Kevin Wimmer has claimed that "too many mistakes" cost FC Koln the opportunity to cause an upset against Bayern Munich at the Allianz Arena.

Bayern scored twice in the opening 10 minutes to force the visitors onto the back foot on Friday night, and despite an impressive response from Peter Stoger's side, the champions managed to finish strongly to secure a 4-1 victory.

"We started the game really badly and conceded two goals early on. We knew we'd have to change something and close the spaces down," Wimmer told reporters.

"We didn't defend well in the first few minutes and made it too easy for them. After about 20-25 minutes we got into the game a bit better. We started being bolder going forward and got one back at just the right time.

"We had a couple of opportunities after the break but when they've got such a good goalkeeper then it makes it twice as hard. We played well at times but in the end it wasn't enough because we made too many mistakes."

Koln return to action against Freiburg in the third round of the DFB-Pokal on Tuesday.