Second-placed Borussia Dortmund are waiting on the fitness of key defenders Mats Hummels and Lukasz Piszczek for Sunday's Bundesliga match at home to strugglers Hoffenheim.

Dortmund need to beat Hoffenheim to close the 11-point gap behind league leaders Bayern Munich, who won 2-0 at Wolfsburg on Saturday, ahead of next week's showdown at Borussia's Signal Iduna Park against Pep Guardiola's Bavarian giants.

Borussia face three games in six days as they also play Darmstadt away on Wednesday before welcoming rivals Bayern.

Hummels, Dortmund's captain and centre-back, was replaced at half-time in their 1-0 Europa League win at Porto on Thursday with a hip problem, but hopes to play, while right-back Piszczek is struggling with a leg injury.

Germany winger Marco Reus is expected to face Hoffenheim despite a groin strain.

Hoffenheim are second from bottom, but Julian Nagelsmann, the youngest ever Bundesliga coach at just 28, stopped the rot last week with a 3-2 win at home to Mainz.

"I'm expecting a tactical and very flexible opponent," said Dortmund coach Thomas Tuchel as his side looked to brush off the effects of their away match in Portugal.

"We have to be fresh and up for it," added Tuchel.