Dortmund's Polish trio fit for German Cup clash at Bayern

Borussia Dortmund's three Polish internationals will be in the squad when the holders visit Bayern Munich in the German Cup quarter-finals on Wednesday.

Midfielder Jakub Blaszczykowski returned to training on Monday after a minor injury and fellow countryman Lukasz Piszczek will also make the trip to Munich after the defender had treatment on his hip problem, said coach Juergen Klopp.

"Kuba (Blaszczykowski) looked good today...and he will be at our disposal," Klopp told reporters.

Poland striker Robert Lewandowski, serving a three-game suspension in the Bundesliga after being sent off, is also eligible to play against Bayern amid widespread media speculation he could join the Bavarians at the end of the season.

Klopp's team are unbeaten in their last six games in all competitions against Bayern.

"An average performance will not do because then we will have no chance against them," said Klopp of the Bavarians who are 17 points ahead of second-placed Dortmund in the Bundesliga.

"We do not have the quality to go to Munich and beat them with 98 percent of effort."

The Ruhr valley club won back-to-back Bundesliga titles in 2011 and 2012 and also beat Bayern in last year's German Cup final to clinch the domestic double.

"On good days we can do unusual things and our opponents know that," added Klopp.

"Three years ago we had to go way back into the history books to see when Dortmund got something from a game against Bayern. This has since changed."