Bayern Munich boss Niko Kovac has predicted a "fierce battle" when RB Leipzig put their 100 per cent record on the line against the Bundesliga champions.
Leipzig have made a perfect start to the season with wins over Union Berlin, Eintracht Frankfurt and Borussia Monchengladbach.
Bayern began the weekend in second spot behind Leipzig, having dropped points in an opening 2-2 draw with Hertha Berlin.
"Leipzig have made enormous progress over the last few years, but we've grown too," head coach Kovac said on the the official club website.
"It'll be tight – a fierce battle. In their early matches there were periods when they pressed high up the field.
"But there were also periods when they dropped deep. We must prepare for this combination.
"They will push us to our limits. But we're the reigning champions and we'll travel to Leipzig with confidence."
Kovac says he will assess players individually after their spells away on international duty.
Canada's Alphonso Davies and Brazil's Philippe Coutinho only returned to Munich on Thursday following their long trips to the Caribbean and the United States.
Thomas Muller, who turned 30 on Friday, could be selected if Coutinho is not fully fit following Brazil duty in Los Angeles.
"We need fit players and we'll talk to the lads," Kovac said.
"Besides Coutinho and Davies, other players have contested intense matches too."
Bayern are definitely without midfielder Leon Goretzka, who has undergone thigh surgery.
Goretzka suffered the injury during Germany's preparations for their Euro 2020 qualifier with Holland and faces a spell on the sidelines, although Bayern have not specified for how long.
"Leon is feeling good, he's glad he's taken this step," Kovac said.
"We hope he'll be back as soon as possible. But it's too early to make exact predictions."
Free-scoring Leipzig have found the net nine times this season, with Germany striker Timo Werner claiming five of them.
But Leipzig did not score against Bayern in their three meetings last term.
"We have to act courageously against Bayern Munich and trust ourselves to win," Leipzig head coach Julian Nagelsmann said at his pre-match press conference.
"We are currently in a good mood and have a run.
"We have to defend strongly, but we can not ignore our offensive play.
"It is crucial that we are efficient against Bayern and take our chances as we will probably not get too many.
"Individual quality can always be crucial, so Timo Werner will be an important factor for that as he is able to hurt Bayern."
On what the psychological impact of beating Bayern would be, Nagelsmann added: "Good results against them can take you a long way.
"But you have to keep performing every week. If we win against Bayern and then lose every other game, it counts for nothing."
Leipzig welcome back defender Dayot Upamecano after injury, but Patrik Schick is doubtful and Kevin Kampl (ankle) and Tyler Adams (groin) remain out.
