FRANKFURT, Germany (AP) — Next-to-last Hamburger SV hosts Borussia Dortmund as it begins its struggle against relegation under a new coach, while runaway leader Bayern Munich visits Hannover in the 22nd round of the Bundesliga.
Here are five things to know about the Bundesliga weekend:
NEW HAMBURG HOPE:
Mirko Slomka took over on Monday from Bert van Marwijk after Hamburg's seventh straight Bundesliga loss. Hamburg is the only founding member of the Bundesliga not to have been relegated in the competition's 51 years, but now it sits only one point above the bottom and three points away from safety. What sealed van Marwijk's fate was the 4-2 loss at bottom-place Eintracht Braunschweig.
Slomka, Hamburg's third coach this season, saved Hannover from relegation and took it to the Europa League, but was sacked in December after losing all away games in the first half of the season.
His first job will be to improve Hamburg's defense, which has given up a league-high 51 goals — conceding three goals or more in 11 games this season, an all-time club record.
The job will be harder knowing that Dortmund's forwards Pierre-Emerick Aubameyang and Robert Lewandowski have already combined for 27 goals this season and that Dortmund is coming off three straight wins. Dortmund is one point away from second place.
Big-spending Wolfsburg is beginning to reap the profits on its investment in new players, including former Chelsea midfielder Kevin de Bruyne, and is hopeful of more success when it hosts Bayer Leverkusen on Saturday.
After 15 rounds, Leverkusen was 11 points ahead of Wolfsburg; now the gap is only four. Leverkusen has lost its last three games, including a 4-0 drubbing at home on Tuesday by Paris Saint-Germain. It is now 16 points behind Bayern Munich.
Wolfsburg has won its last three and is now in fifth place, beginning to look at Champions League slots. Wolfsburg has won its last three home games against Leverkusen.
Schalke has won all four matches after the mid-season break — the best start in a new year in 12 years — and is two points behind Dortmund in fourth place.
Schalke is unbeaten is six matches as it hosts Mainz on Friday. Mainz already has 10 victories this season and has won four of its last five, but has beaten Schalke only once in the past 11 games.
Schalke's coach Jens Keller appeared to be on the way out late last year after a string of pale performances but the club stuck with him and Schalke's fortunes have picked up, especially with the return from injury of striker Klaas-Jan Huntelaar.
Another former Bundesliga champion in free fall is Stuttgart, which has lost six straight and is two points away from the danger zone as it prepares to host Hertha Berlin.
With five wins, four draws and 12 defeats, Stuttgart has never had a worse record after 21 rounds in the club's history.
Promoted Hertha is a surprise of the season sitting in eighth place. It has spoiled its record by losing three of its last four matches but has won four of its last five away from home.
Eintracht Frankfurt and Werder Bremen are both at 21 points and trying to leave the danger zone behind them as they head to their showdown in Bremen.
Bremen has won only one of its last 10 matches. Bundesliga statistics say both teams concede early, but Eintracht has also lost a dozen points by giving away late goals.
Eintracht failed to win a home match in the first half of the season, the main reason it is so low in the standings. Its top scorer Alexandar Meier will be making his 200th Bundesliga appearance.