Germany winger Marco Reus has refused to press charges of grievous bodily harm against a defender for a foul during a German Cup match, despite a two-month long police investigation.

Reus lasted just 24 minutes of Dortmund's 2-0 third-round win over third-division Dynamo Dresden and was left with a knee injury after being fouled off-the-ball by Dresden defender Dennis Erdmann.

Having investigated Erdmann for what was seen as a malicious, rather than sporting challenge, Dresden police have confirmed they have closed the matter.

"We've closed the case because the affected player has not made a complaint," a spokesman for the Dresden Prosecutor's Office told SID, an AFP subsidiary.

Reus advisor Dirk Hebel told German daily Bild that the German international was sent a form by Dresden police asking if he wanted to press charges, but declined.

"He didn't want the player to be prosecuted," explained Hebel after his client was left with a bruised knee from the incident.

Having missed Germany's World Cup win last July with an ankle injury, Reus has endured an injury-ravaged season and to add insult to injury, Erdmann had mocked the Dortmund star after he was helped off in Dresden.

"I used to play in the regional league and when you'd get a knock like that, you'd give it a rub and play on. I don't think it's like that in the Bundesliga," said Erdmann after the match.

Reus has himself been in trouble with police this season after being fined 540,000 euros ($600,374) last December for driving without a licence since 2011.

Dortmund will play VfL Wolfsburg at Berlin's Olympic Stadium on May 30 in the German Cup final and hope to have Reus fit.