Borussia Dortmund defender Julian Ryerson is doubtful for their mini-Ruhr valley derby against VfL Bochum on Saturday, coach Edin Terzic said on Thursday.

Dortmund, last season's runners-up who missed out on the title after a final day slip-up, won their opening Bundesliga match against Cologne last week thanks to an 88th minute goal from Donyell Malen.

Against hosts Bochum Terzic could be without Norway international Ryerson who picked up an injury in the first game, the coach told a press conference.

Terzic said it may not be the big match with now-relegated Schalke 04 that all of Germany associate with the Ruhr derby but Bochum were determined to give them a run for their money.

"After their 5-0 loss to VfB Stuttgart last week Bochum will want to get a lot out of our match on Saturday and we have experienced how difficult it is to play there."

Dortmund dropped two hugely important points in a 1-1 draw there late last season.

"We have prepared for the match. Since Sunday we have been talking about it, what to expect from them," Terzic said.

"Obviously when you talk about the derby everyone in Germany thinks of Dortmund against Schalke. But in the past few years we have felt how important this game is for Bochum.

"We are definitely ready for this day, no matter how fiery and loud it may be. We will try turn it into a Dortmund game. We want to rectify some things there."