Bayern Munich's Spanish midfielder Juan Bernat warned the German champions' fans not to expect another 7-1 rout when they host AS Roma in the Champions League on Wednesday.

Pep Guardiola's side can secure their place in the knockout phase if the Group E leaders pick up their fourth straight win.

But Bernat says Bayern can expect a much tougher evening against Roma, who are second in the group five points adrift, in contrast to the game last month when the Germans set a new club record for an away win humbling the Italian outfit 7-1.

"It will be a completely different game to the away fixture," said Bernat.

"The first leg was perfect for us, it was a crazy game, but now things start again at zero.

"It will be difficult and very competitive."

Bayern are unbeaten this season and maintained their iron grip on the Bundesliga on Saturday with a 2-1 come-back win at home to Borussia Dortmund.

However, despite their superb form Bayern left-back David Alaba also warned his team-mates to be wary of a Roma side boasting the likes of veteran Italian international midfielder Daniele De Rossi.

"Roma is a strong team and they will come here to take points and have players who can decide a game single-handedly," said Alaba.

"But we are still very hungry and ambitious."

Roma coach Rudi Garcia is missing injured defenders Leandro Castan, Davide Astori (both thigh) and Brazilian Maicon (knee) for the trip.

Bayern will also have important players absent in the shape of long-term injury victims Bastian Schweinsteiger, Javi Martinez and Thiago Alcantara.