Hansi Flick aims to plug Bayern Munich's leaky defence ahead of battle of big beasts against Borussia Dortmund

One week on from a 5-1 humiliation at Frankfurt that led to the sacking of Kovac, Bayern's interim manager faces major test at home to old rivals

Bayern Munich's interim manager Hansi Flick watched his team beat Olympiakos in the Champions League on Wednesday. EPA

Bayern Munich interim manager Hansi Flick has his work cut out for him as he seeks to plug the champions' leaky defence and inspire some confidence ahead of Saturday's Bundesliga battle with Borussia Dortmund.

Assistant manager Flick was put in temporary charge after Niko Kovac was sacked in the wake of Bayern's humiliating 5-1 drubbing at Eintracht Frankfurt.

That defeat left Bayern in fourth place, four points off surprise leaders Borussia Monchengladbach in the tightest Bundesliga title race in years.

Long-term injuries to defenders Niklas Suele and Lucas Hernandez present a major problem for Flick with Bayern leaking goals all season and facing one of the league's most potent attacks at the Allianz Arena.

Bayern have conceded 16 goals in 10 league games, the same as strugglers Fortuna Duesseldorf and more than 14th-placed Union Berlin.

"We will undertake one or two changes," Flick said after his first training session this week. "The way we have been conceding goals is not very Bayern-like.

"It is important for the team to be active. We have to defend from the front and try to get the ball back as quickly as possible. Those are the points we want to address."

Bayern took a step forward on Wednesday, beating Olympiakos in the Champions League 2-0 for their first clean sheet in all competitions since September 21.

But it is not just the defence that Flick, a former Germany coach, must address. Confidence is a major issue for a side who find themselves in an unfamiliar position after dominating the league for years.

Bayern have won the last seven consecutive league titles, the best run in the history of the Bundesliga, but they have not been firing on all cylinders this season.

High-profile signing Philippe Coutinho has been disappointing so far, while the club has depended almost exclusively on Robert Lewandowski's scoring ability with the prolific Pole having netted 14 times in 10 games so far.

Former Arsenal manager Arsene Wenger has been linked with taking over at Bayern, although the Frenchman has denied talks have taken place.

The 70-year-old, who has not taken on a coaching role since leaving the London club at the end of 2017-18, said: "I never refuse to talk to Bayern Munich because I know these people who lead the club for 30 years.

"I was nearly going to Bayern a long, long time ago. At the moment, I haven't talked to them at all. We have not talked to each other and I don't know [if we will]."

Dortmund will be going into the game brimming with confidence after their 3-0 win over the previously unbeaten Wolfsburg in the Bundesliga last week and their comeback victory over Inter Milan in the Champions League on Tuesday.

Dortmund, in second place on 19 points, one ahead of Bayern, were trailing 2-0 at half-time against the Italians before scoring three times to clinch victory.

But their record in Munich is woeful and Dortmund have lost all five of their last Bundesliga trips to the Bavarian capital, with scores of 2-1, 5-1, 4-1, 6-0 and 5-0.

And, despite their recent upheavals, Dortmund Sporting director Michael Zorc is expecting the usual tough contest.

"The lads in Munich will pull themselves together for this game, regardless of who's coaching them," Zorc said. "And we will have to hold our own. We failed to do that last year and in most recent years. This is the clear demand for our players."

Manager Lucien Favre insisted that his team's record there is not a concern. "In the last five years, it has been hard to win there," he said. "But, we have nothing to lose. We respect Bayern – we don't fear them."

Captain Marco Reus and Jadon Sancho will undergo fitness tests to decide whether they are fit enough to play. Reus is doubtful due to ankle problems, while Sancho is struggling with a thigh strain.

Leaders Gladbach, who beat Bayer Leverkusen 2-1 last weekend, then continued their run of form by defeating Roma by the same scoreline in the Europa League on Thursday.

A winner five minutes into injury time from Marcus Thuram secured a first group stage win at the fourth attempt and put Die Fohlen in good shape to host Werder Bremen in the Bundesliga on Sunday.

Thuram, the son of France's legendary World Cup winning defender Lilian, was hailed lauded by teammate Denis Zakaria after the Italian giants were beaten at Borussia-Park.

"It was so important that Marcus scored that goal today. He is a great guy, a little crazy maybe, but what he brings to the pitch is phenomenal," Zakaria said.