Hamburg, Feb 4 : High-flying Bayern Munich have revenge in mind when they visit champions VfL Wolfsburg in Saturday's Bundesliga programme.

Munich were humiliated 5-1 in Wolfsburg last season, with Grafite's infamous back-heel goal the most lasting memory from that table-topper in April 2009.

But the times have changed dramatically since then.

Juergen Klinsmann got his marching orders as Munich coach a little later and the club now ranks second with seven straight victories and 13 league matches without defeat under Louis van Gaal.

Wolfsburg saw coach Felix Magath leave for Schalke last summer. His successor Armin Veh was recently sacked and caretaker Lorenz-Guenther Koestner takes a winless team run of 13 competitive matches into a tricky fortnight with games against Munich, at current leaders Bayer Leverkusen and against third-placed Schalke.

"We can not be afraid," said Koestner ahead of the game, calling for a fighting effort from his 11th-ranked team.

But Munich come to Wolfsburg in fine form and van Gaal can afford to leave Franck Ribery out of the starting 11 in his comeback from injury.

"He will come back even stronger than before. Franck will play when I believe that he can make a bigger impact than others," van Gaal said.

Bayern will not want to drop any points on a rare day in which the leading trio play at the same hour on Saturday. Leverkusen take 44 points into a match at lowly VfL Bochum, Munich have 42, and Schalke (41) are also on the road, at struggling SC Freiburg.

The scheduling allowed Munich to top the table for 24 hours the past three rounds as Leverkusen played a day later. But Jupp Heynckes' team did not crack under pressure and remain the only unbeaten Bundesliga team.

But Heynckes and defence stalwart Sami Hyypia warned that Leverkusen can not afford to allow the opposition chances like in Sunday's 3-1 win against Freiburg.

"We will only be successful if we are positioned well in defence," said Heynckes. Hyypia warned that "things can go wrong" and called for a better defensive effort in Bochum.

Schalke have kept quietly in contention, while Borussia Dortmund (36 points) and SV Hamburg (35) appear out of the title race.

New Hamburg star hiring Ruud van Nistelrooy will likely not play in Cologne on Saturday, not even as a sub, as coach Bruno Labbadia wants the Dutchman to fully recover from a calf muscle injury.

"We don't want to take the risk of fielding him too early," said Labbadia, calling for patience.

The weekend action starts on Friday when ailing Werder Bremen, winless in seven games and losers in the last five, take on bottom side Hertha Berlin.

The other Saturday games are Nuremberg v VfB Stuttgart and TSG Hoffenheim v Hanover 96. Sunday's fixtures are Dortmund v Eintracht Frankfurt and Mainz 05 v Borussia Moenchengladbach.(DPA)