For the first time since the virus hit Europe in mid-March, the German Football Association (DFB) had planned to let several thousand fans in to watch the home international in Cologne.
However, the number of new cases of Covid-19 in the city is 37.4 per 100,000 inhabitants - above the limit of 35 set by the health authority - for fans to be admitted.
The German FA is waiting to be told whether the friendly must be played behind closed doors.
"We have great confidence in the decisions of the authorities and will comply with the relevant requirements without any discussion," said German FA president Fritz Keller.
"At the same time, we have not given up hope that fans can be admitted to watch the national team again," he added with ticket sales continuing.
On Saturday, Cologne's 3-1 home defeat against Borussia Moenchengladbach at the Rhein Energie Stadium, where Germany will face Turkey, was played behind closed doors.
Wednesday's friendly is of particular interest given the tense relations between Turkey and Germany, which is home to a large Turkish community.
The DFB also wants to make one of it's home matches free of charge to the public as a 'thank you' to German fans for their support during the pandemic.
The friendly against Turkey is a warm-up before Germany plays Ukraine away on Saturday, then hosts Switzerland on October 13 in Nations League games.
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