Borussia Dortmund coach Thomas Tuchel has lowered his side's expectations ahead of Sunday's German Super Cup.

Dortmund face Bayern Munich at the Westfalenstadion with the first trophy of the German season at stake -- but Tuchel is not sure his side are yet in the right condition to beat the defending Bundesliga champions and DFB-Pokal holders.

"Of course everybody wants to win the Supercup, but I also wanted to beat Athletic Bilbao [in a friendly]," Tuchel told Sport1 television.

"Having analysed this game, we would be well advised not to have too high expectations for the Supercup."

Dortmund have beaten Bayern twice in the past three editions of the Super Cup, although they were also the last side Bayern won to lift the trophy in 2012.

Bayern also got the better of the Westphalians in last May's DFB-Pokal final, with Sven Bender and Sokratis Papastathopoulos both missing in a penalty shootout which saw Pep Guardiola's side complete a league and cup double.