Knee surgery sidelines Bender

Borussia Dortmund midfielder Sven Bender is set to be sidelined for a month after undergoing knee surgery.

The Germany international twisted his knee on Wednesday and subsequently went under the knife on Friday.

Dortmund announced that the surgery was a success and that a recovery period of approximately four weeks is required.

"Borussia Dortmund's Sven Bender twisted his knee on Wednesday," read a statement on Dortmund's official website.

"The midfielder was successfully operated on today [Friday].

"Dortmund team doctor Markus Braun expects a downtime of about four weeks."

Bender has made 13 league appearances for the Bundesliga strugglers this term.

Jurgen Klopp's men entered the mid-season break in the relegation zone having won just four of their 17 league matches.

Dortmund resume their campaign at Bayer Leverkusen on January 31.