Rudi Voller says Bayer Leverkusen are in their toughest spell since he has been at the club. Simon Hofmann/Bongarts/Getty Images

Bayer Leverkusen sporting director Rudi Voller has warned that "our existence is at stake" as they battle to avoid falling into the relegation playoff place.

Leverkusen have picked up just six points from eight games under new coach Tayfun Korkut, meaning their Bundesliga status is not yet secure.

As they prepare for a crucial weekend match against struggling Ingolstadt, Voller told WAZ the club were in the most difficult position of his 16 years at the helm.

He said: "We are talking about a relegation fight here. Our existence is at stake.

"It's dangerous. The pressure is huge. But we will face it."

Voller added that he believed Leverkusen had "bought well" in the summer and "many experts have confirmed that," adding: "We felt so much euphoria before the season, but football has no logic. And of course we did a few things wrong."

He said "nobody can know for sure" whether Leverkusen had waited too long to sack previous coach Roger Schmidt, who was dismissed in March.

He added: "It has never been so hard for me to sack any coach as it was to sack him.

"I still rate him as a great coach. Some say it was too late, others say it was too early. But nobody can know for sure."

Leverkusen are without Germany attacker Julian Brandt, 21, who is nursing a muscle injury.

"There was a lot of pain again in his muscles, and the risk that it will turn into a bigger injury was too high," Korkut told a news conference.

Defenders Jonathan Tah and Omer Toprak both made the trip despite injury problems, and it remains unclear whether they will be able to play.

"It'll be a race against time," Korkut said, urging his team to "show their qualities and not only bank on fighting spirit."