Adler ensured Leverkusen picked up a 0-0 draw at Hannover yesterday with a string of world-class saves, also ensuring that Leverkusen remain at the top of the Bundesliga with two games to go before the midway stage of the campaign.

However, Adler's team-mates were unable to show their usual form as they laboured in vain to find a goal.

"We were lacking quite a lot today," said Heynckes.

"We lacked precision with our passing and were not so comfortable on the ball in midfield or as well organised.

"It was a strange game and maybe a draw is fair in the end, although Hannover were a touch better than us.

"Adler had to make several excellent saves."

Including the five games Heynckes led as coach of Bayern Munich at the end of last season, he has now not tasted defeat in 20 consecutive Bundesliga matches.

And he does not yet think his side is playing to their full potential.

"When we have our full squad available again, and I don't want to be threatening, then we will be even better," he added.

Leverkusen should have striker Patrick Helmes back in the new year after he tore cruciate knee ligaments in pre-season training.