Bayern Munich chairman Karl-Heinz Rummenigge said Tuesday he regrets the absence of Borussia Dortmund in this season's Champions League, especially with the 2011 and 2012 German champions currently leading the Bundesliga.

Bayern start their Champions League campaign on Wednesday at Greece's Olympiakos in Group F with Arsenal and Dinamo Zagreb also in their pool.

Dortmund, meanwhile, find themselves in this season's Europa League after finishing seventh in the Bundesliga in Jurgen Klopp's final campaign in charge and losing to Wolfsburg in the German Cup final.

Under new coach Thomas Tuchel, Dortmund have won their opening four Bundesliga games and top the table from Bayern on goal difference.

Dortmund host Russia's FC Krasnodar on Thursday in their opening Europa League Group C match, but Rummenigge says Borussia's absence will be felt in the Champions League, especially after Bayern and Dortmund contested the 2013 final.

"They actually belong there. Dortmund has always been a good guarantor for German football," said Rummenigge before Bayern jetted off to Athens.

"They have always progressed and collected valuable points.

"Dortmund has done well up until now -- and will continue to do so."

Rummenigge said he hopes the four German clubs in this season's Champions League -- Bayern, Borussia Moenchengladbach, Wolfsburg and Bayer Leverkusen -- will "carry the German flag quite so well. We need the points".

With third-placed England hard on Germany's tail in UEFA's club co-efficient rankings behind leaders Spain, Rummenigge says German clubs need to do well in Europe to keep ahead of their Premier League rivals.

Rummenigge also says he expects French winger Franck Ribery to play again in 2015, despite the France international having been blighted by a right ankle injury which has kept him sidelined since March.

"I think it will be the case that he will definitely be darting around again in 2015," added Rummenigge, although Bayern have given no date for Ribery's return.

"He will make a comeback, that is crucial."