Berlin: The Bundesliga returned to action last night when runaway leaders Bayern Munich were hosted at Bayer Leverkusen.

Second-placed Schalke, who are 11 points behind the Bavarians, play today at fifth-placed RB Leipzig who are fending off speculation rife about Liverpool-bound Naby Keita.

Pierre-Emerick Aubameyang promises he has something up his sleeve, as he battles with Bayern’s Robert Lewandowski to be the league’s top-scorer, when Borussia Dortmund host Wolfsburg tomorrow.

Borussia Moenchengladbach are out to inflict more misery on bottom side Cologne, who are already planning for life in the second tier.

Aubameyang is two short of 100 Bundesliga goals and plans a surprise if he reaches the milestone at home against Wolfsburg.

“I’ve something in mind for when I get there, but it’s a surprise,” Aubameyang said.

The Gabon forward has scored 13 league goals this season, two fewer than Bayern’s Lewandowski, and has again been at the centre of transfer speculation.

Chinese sides Guangzhou Evergrande and Beijing Guoan were reportedly both chasing his signature, which prompted a warning from the Chinese Football Association about “engaging in a bidding war”.

Dortmund captain Marcel Schmelzer admits constant speculation about Aubameyang’s future unsettles the team, which was hit by a stomach bug this week at their Spanish winter training camp.

Schalke are expected to start new signing Marko Pjaca at Leipzig for the Croatia winger’s Bundesliga debut.

The talented 22-year-old has joined on loan from Juventus until the end of the season and has already netted his first goal for the Royal Blues when he opened the scoring in a 2-1 friendly win against Belgian side Genk.

“Marko has a lot of qualities and he is an option to start against Leipzig,” said Schalke coach Domenico Tedesco.

With speculation rife about Keita’s summer move to Liverpool being brought forward, Leipzig seek a home win against Schalke after failing to win any of their five games in December.

Leipzig welcomed Germany striker Timo Werner back to training on Tuesday after illness, but the spotlight will be on Keita at the Red Bull Arena.

The 22-year-old has a Liverpool contract from July 1, but the Reds are reportedly eager to sign him this month to replace Philippe Coutinho.

On Thursday, Leipzig coach Ralph Hasenhuettl insisted Keita will not be leaving before the end of the season.

German magazine Kicker say Keita has trained poorly in a bid to force Leipzig’s hand, but Hasenhuettl says the midfield playmaker will face Schalke — and he expects a good performance.

Keep an eye on Hertha Berlin striker Salomon Kalou at Stuttgart on Saturday.

The 32-year-old, who won the 2012 Champions League title with Chelsea, is on a goalscoring run.

He came off the bench to bag a 91st-minute equaliser in a 1-1 draw at Augsburg on December 10 and netted two first-half goals in a 3-1 win at home to Hanover three days later.

He claimed his fourth goal in three games when Hertha survived a second-half fightback to win 3-2 at Leipzig just before Christmas.

“’Sala’ is a very important man for us and he showed that,” said Hertha forward Valentino Lazaro, who set up Kalou’s goals against Hanover.

Bayern are miles ahead in the table, but things are tight between their pursuers with Moenchengladbach hoping to gain ground.

Just two points separate second-placed Schalke from sixth-placed Gladbach, who expect three points at bottom side Cologne on Sunday.

Even though Gladbach have only won just one of their last five games since shocking Bayern 2-1 in November, they plan more misery for Cologne, who are 11 points from safety.

Gladbach’s Brazil forward Raffael is battling a calf injury.

If he is not fit, Thorgan Hazard is likely to start up front with Germany’s Patrick Herrmann and Italian Vincenzo Grifo on either wing.

Fixtures (all times 1430 GMT unless stated)

Saturday

Werder Bremen v Hoffenheim, Eintracht Frankfurt v Freiburg, Augsburg v Hamburg, Hanover 96 v Mainz, Stuttgart v Hertha Berlin, RB Leipzig v Schalke (1730)

Sunday

Cologne v Borussia Moenchengladbach, Borussia Dortmund v Wolfsburg (1700)