BERLIN: Bayern Munich may be expected to rack up another Bundesliga win against Hoffenheim on Sunday but all is not well with the league leader.

Coach Pep Guardiola is reportedly cracking down as he seeks a treble of Champions League, Bundesliga and German Cup trophies in his last season in charge.

Predecessor Jupp Heynckes managed the feat in his final campaign in 2013.

Despite an eight-point lead over Borussia Dortmund in the league, where Bayern has dropped just five points all season, Kicker magazine reported Thursday the relationship between Guardiola and his players was coming under strain.

The Spanish coach is said to be unhappy with some players' professionalism and their behavior on days off, with trips abroad causing particular annoyance.

Kicker also said Guardiola criticized players for being overweight before the league resumed after its month-long winter break last weekend.

Bayern's injury problems have revealed some tension at the club, with Jerome Boateng's name the latest added to a long list.

The Germany defender has been ruled out until at least the latter stages of the season with a groin injury sustained in last Friday's 2-1 win at Hamburger SV.

Boateng's absence is a blow for Bayern ahead of the Champions League last-16 match with Juventus on February 23.

Bayern chairman Karl-Heinz Rummenigge indicated his frustration when he told the dpa news agency that he recommended the German football federation "keeps back" from Boateng "or there'll be stress with Bayern."

Germany coach Joachim Loew had suggested he would give Boateng every chance to recover for the European championship in France.

Rummenigge also revealed Boateng had consulted former Bayern doctor Hans-Wilhelm Mueller-Wohlfahrt. Mueller-Wohlfahrt had quit Bayern after 38 years in April 2015 after rowing with Guardiola over the club's injury list.

Boateng joins Franck Ribery, Mario Goetze, Medhi Benatia, Rafinha and Sven Ulreich among Bayern's sidelined.

Guardiola will need to come up with solutions, with Xabi Alonso, Holger Badstuber or Javi Martinez likely to fill in.

"I have huge trust in Guardiola and the team," said Rummenigge, despite his consultations with Mueller-Wohlfahrt.

Here are some other things to know about the Bundesliga's 19th round:

DILIGENT DORTMUND

Dortmund will hope to capitalize on any Bayern slip-ups, though publicly at least the club has ruled out a title challenge despite claiming 41 points from 18 games.

Thomas Tuchel's side is unbeaten at home this season and promoted Ingolstadt is the next side to visit on Saturday.

Pierre-Emerick Aubameyang has 12 goals in eight home games for Dortmund, as many as Ingolstadt has scored all season.

The Gabon striker will be hoping to return to scoring ways after enduring a luckless game in last weekend's 3-1 win at Borussia Moenchengladbach.

'GLADBACH'S LEAKY DEFENSE

That defeat to Dortmund was 'Gladbach's first at home in the Bundesliga since Andre Schubert took over as coach.

Early euphoria following his appointment in September has been replaced by concern over defense with 18 goals conceded in the last five competitive games.

Schubert employs a higher line than his predecessor Lucien Favre, giving the side a more potent attack, but opponents have been taking advantage in recent games.

Injuries have also played their part in 'Gladbach's change of fortune.

"We have to find the right balance between defense and offense," sport director Max Eberl said ahead of Friday's trip to Mainz.

WOLFSBURG'S SLUMP

Wolfsburg is without a win in five league games for the first time under coach Dieter Hecking.

The side was left to rue missed opportunities last weekend when Alexander Meier completed a hat trick in injury time for Eintracht Frankfurt's 3-2 win.

Hecking will be hoping for a marked improvement at home against visiting Cologne.