Borussia Dortmund's goal-machine shows no sign of slowing for Sunday's crunch Bundesliga derby clash against Schalke 04 -- even without injured Germany winger Marco Reus.

Dortmund have scored 68 goals in 21 games so far this season under new coach Thomas Tuchel, but will be without groin-strain victim Reus for the home derby against Schalke.

Reus picked up the injury while scoring Dortmund's opening goal in Thursday's 4-0 rout of Armenia's FK Qabala in the Europa League and his place on Dortmund's left wing is set to go to Jonas Hofmann or Gonzalo Castro.

Even after Reus went off, Dortmund still managed to score three more goals through Pierre-Emerick Aubameyang and winger Henrikh Mkhitaryan.

"We still have a wide number of players who are dangerous," said Dortmund's director of sport Michael Zorc as only leaders Bayern Munich have scored more goals in the Bundesliga.

"That's what makes a good team."

While Dortmund have had no trouble finding the net, Schalke have struggled in front of goal and only netted 14 goals in 11 games this season.

That's just one more than Borussia's Gabon striker Aubameyang has managed on his own in Germany's top flight this season in a total tally of 21 goals in all competitons.

"It's a really important game for Dortmund fans... you can lose all your matches, but the derby is the one they want you to win," said Aubameyang.

"I'm sure we'll win, because we're at home and the team is playing well."

Borussia are second in the table and have won their last six games, while Schalke are down to fifth and winless in their last five, but form counts for little in a derby, according to Royal Blues midfielder Leon Goretzka.

"You shouldn't pay too much attention to what the current table says before a derby," he said after their 1-1 draw on Thursday at Sparta Prague in the Europa League.

"Even if we're 18th and Dortmund are first, you can still win."

Dortmund trounced Schalke 3-0 when the teams last met at Borussia's Signal Iduna Park stadium in February as the hosts fired in 31 shots on goal, while the Royal Blues set a league record low of just three in reply.

"We have a little something to make up," admitted Schalke's goalkeeper Ralf Fahrmann.

Schalke's top scorer is teenage rising star Leroy Sane, who has netted four times in 11 games and his eye-catching displays have led to the 19-year-old being called up to Germany's senior squad for forthcoming internationals against France and the Netherlands.