Arjen Robben insists that Bayern Munich are not good enough to retain their Bundesliga crown as the off-form champions prepare for the visit of strugglers Fortuna Duesseldorf on Saturday, with their title-winning streak under threat.

Bayern have won the last six German titles but they currently trail leaders Borussia Dortmund by seven points after losing three of their last six league games.

“We’re not in a position to talk about the title at the moment – we simply aren’t good enough,” veteran winger Robben, 34, told broadcaster ARD.

Their latest defeat came 3-2 at Dortmund’s Signal Iduna Park a fortnight ago, and left head coach Niko Kovac in a precarious spot.

Bayern’s outspoken chairman Uli Hoeness says he will back Kovac “to the end”, but patience could wear thin should Bayern drop lower than sixth and outside the European places.

However Hoeness says it is up to Bayern’s stars to get the club back in the title race, warning that “the players are under pressure for the next three of four months”.

“Then we will see who is needed and who isn’t,” he said.

Despite their poor run Bayern are heavy favourites to pick up three points against second-from-bottom Fortuna, whose midfielder Matthias Zimmerman joked about “parking the team bus” in their goal at the Allianz Arena.

“Everyone thinks we’re going to lose, but we have to be brave and approach the job with joy and fun. Perhaps we’ll manage a miracle,” said Zimmermann, whose team have leaked 15 goals in their last four games.

However Duesseldorf sparked cause for optimism after pulling off a surprise 4-1 win at home to Hertha Berlin last time out.

Dortmund welcome Diallo

Dortmund, the Bundesliga’s only team unbeaten, have a tricky away trip on Saturday to Mainz, who ended a seven-match winless streak by beating Bremen and Freiburg in their last two matches.

Dortmund’s defensive casualty list has eased, with Abdou Diallo available to face his former club after missing the last two games with a groin injury and playmaker Marco Reus recovering from a bruised foot.

The league leaders are targeting a more consistent display performance against Mainz after being well outplayed by Bayern in the first half before scoring three goals after the break.

“We’re taking it one game at a time,” said sports director Michael Zorc.

“Confidence is growing, but we had problems in the first half (against Bayern), we’re starting again at 0-0 and we have to be focused.”

Second-placed Borussia Moenchengladbach, who have won all five of their home league games this season, host third-from-bottom Hanover 96, who have not won any of their last 18 away league matches – dating back a year.

‘Gladbach are chasing their third straight win with Belgian winger Thorgan Hazard on fire.

The younger brother of Chelsea star Eden Hazard has scored 10 goals in 13 games for ‘Gladbach and netted twice for Belgium in their shock 5-2 capitulation to Switzerland on Sunday.

However, his contract expires in 2020 and Gladbach want him to sign an extension.

“Thorgan has been with us since 2014 and has improved consistently,” sports director Max Eberl told magazine Kicker.

“We’ll sit down in the spring and talk again.”