Bayern Munich midfielder Toni Kroos has warned that his side are far from reaching top form, despite making an unbeaten start to their Bundesliga campaign.

Pep Guardiola's men have claimed four wins and a draw in their opening five league games but still drew criticism from sporting director Matthias Sammer last week, who feels that their performances have lacked effort.

Kroos told reporters at a pre-match press conference: "Until now we have won our games but perhaps we did not play as good as we could have. This could be a danger in our next games.

"Matthias Sammer has every right to give his opinion about our performance on the field. We are looking forward to this season a lot. And it is something special to go in this season as defending champions.

"We remember last season which was quite special and now it is the beginning again, something which could be very special again. We want to start with a win in this group stage."

Bayern begin their defence of their Champions League crown later tonight in a Group D opener against CSKA Moscow at the Allianz Arena.