BERLIN, Sept 29 — Bayern Munich’s four-game winless run — their longest in the Bundesliga in 20 years — has soured the mood among club bosses and piled pressure on coach Julian Nagelsmann to quickly turn things around.

With the Klassiker at Borussia Dortmund awaiting next week, fifth-placed Bayern, whose last win was in August and who are five points off top spot, will have their backs to the wall tomorrow at home to fellow Champions League club Bayer Leverkusen.

Any slip-up going into a week that apart from the Dortmund game also has Bayern hosting Viktoria Plzen in the Champions League group stage on Tuesday, could prove decisive for the future of Nagelsmann at the club.

Fourth-bottom Leverkusen have fared far worse and have managed just one win from their seven Bundesliga matches as they prepare to visit Porto in the Champions League on Tuesday.

The 35-year-old Nagelsmann, in his second season at Bayern, still enjoys the full backing of the board.

"Internally there is absolutely no additional pressure,” club CEO Herbert Hainer told BR television. "We are always under pressure at Bayern because we want to win but you have seen how all of us (club bosses) are fully behind Julian Nagelsmann.”

Success-spoilt Bayern fans have been far less patient with the coach during their winless run, especially after Bayern failed to hold on to top striker Robert Lewandowski, who left to join Barcelona in the close season.

Nagelsmann landed one trophy last term, their 10th straight league crown, but his team was bundled out of the Champions League in the quarter-finals by Villarreal.

"At the end of the day in football it’s results that always matter and that is why we have to win on Friday,” Hainer said.

Nagelsmann has a full squad to choose from but has seen some players, including Sadio Mane and Serge Gnabry, struggle with their form recently.

Bayern also wasted scores of chances as they drew three and lost one of their last four Bundesliga matches.

"The season is not one-sided, negative or positive,” Hainer said. "We had a great start and now we are struggling a bit.”

"We still have created an enormous amount of chances.”

They will need to convert them if they are to remain in touch with the top spots as Bayern’s recent run saw them drop to fifth place with 12 points behind leaders Union Berlin on 17.

The Berliners, the only undefeated team left in the league, travel to Eintracht Frankfurt on Saturday. Dortmund, in second place on 15, visit Cologne. — Reuters