Hans-Jorg Butt failed to keep a clean sheet for Bayern Munich's 4-1 win over AC Milan.

Butt flapped at a free-kick from Andrea Pirlo and was unable to make what should have been a standard save.

With Bayern coach Louis van Gaal yet to make his mind up between Butt and Michael Rensing for the number one jersey this season, such a mistake may prove costly.

"It was a free-kick and I should have put three men in the wall so I have to accept responsibility," he said.

Nevertheless, the former Bayer Leverkusen and Benfica custodian remains confident that he will be given the nod by Van Gaal for Saturday's DFB-Pokal tie with Neckarelz.

"I just want to carry on from where I left off last season, which was as number one for Bayern Munich," he added.

Van Gaal would not be drawn on whether Butt's mistake could cost him his place in the side.

He has confirmed that he will choose his number one in the next few days and whoever starts in goal at the weekend will be his first choice, at least for the start of the Bundesliga season.