Bayern Munich defender Philipp Lahm conceded that the Bavarians suffered from sloppy defending of late. The German giants leaked four goals in their last three games, which cast doubts over the competence of their backline. Lahm believes the whole team are to blame for the rearguard's drawbacks. "We do not work on our defensive duties," the 26-year-old told Bild. "The problem lies in the behavior of the whole team, that's why the last three games were not as good as before. "We must once again get a grip on ourselves. Otherwise, it will be difficult in the Champions League." Bayern will host Serie A outfit Fiorentina on Wednesday in the continental competition's knock-out stage. Louis van Gaal's side are keeping pace on top of the Bundesliga table with 48 points.