Borussia Dortmund have lost their status as Bundesliga leaders and Pierre-Emerick Aubameyang has stopped scoring, but coach Peter Bosz denied talk of a crisis before Wednesday's Champions League tie against APOEL.

"There was no crisis - and there is no crisis - Hanover were just more aggressive than us," Bosz insisted after Saturday's 4-2 defeat at Hanover 96 saw Bayern Munich replace Dortmund at the top of the Bundesliga.

Nevertheless, Dortmund face an uphill fight to reach the knockout stages of Europe as they trail both Real Madrid and Tottenham Hotspur by six points in Group H after three matches.

Defeats by Tottenham and Real, before a draw at APOEL in Nicosia a fortnight ago, have left Dortmund, Champions League finalists in 2013, facing a group-stage exit.

Yet Bosz still harbours hopes of reaching the last 16.

"You have to keep believing, it's still not over and tomorrow's game is important for us," said the Dutchman.

But all is not well in the Dortmund camp.

A 5-0 German Cup victory at third-division Magdeburg last week is Dortmund's only win in their last five games.

To make matters worse, Aubameyang, the Bundesliga's top scorer last season, is goalless in his last three games despite netting 15 times in all competitions so far this term.

"When Aubameyang, or a striker in general, doesn't score goals, criticism will follow and it will be discussed," said Bosz.

"But when he works hard and the team plays well, everything is fine.

"Every striker has phases when he doesn't score in one, two or three games and I am certain he will score again soon."

APOEL will fancy their chances at Dortmund's Signal Iduna Park where defeat will end either team's hopes of progressing to the next stage.

The teams drew 1-1 in the first meeting when a blunder by Dortmund goalkeeper Roman Burki saw Mickael Pote give APOEL a shock lead before defender Sokratis Papastathopoulos equalised with a header.

- 'Focus on Plan A' -

On Saturday, Dortmund's shaky defence was brutally exposed by Hanover 96, who mercilessly dismantled the visitors with a series of counter-attacks.

For the third league game in a row, Dortmund's defence left far too many holes to exploit.

"We have analysed the game against Hanover and we're happy that we can play again at home," said captain Marcel Schmelzer.

"Our attitude wasn't good enough (at Hanover) and we quickly need to find the form which has made us strong."

The German media is blaming Dortmund's struggles on Bosz's 4-3-3 system and the Dutchman said it is important his team regain their confidence.

"We have a Plan B for when things go wrong, but it's more important that we focus on our Plan A, which didn't work in Hanover," said Bosz.

"We have to concentrate on our game."

In the space of two weeks, Dortmund have seen a five-point lead evaporate and they now trail Bayern by three points in Germany.

Dortmund and Bosz need a win, not just to boost their fading Champions League chances, but to get their entire season back on track.

source: AFP