File Photo: German government spokesperson Steffen Seibert taken on August 28, 2020 in Berlin. AFP
"We are concerned and puzzled by the comments made by the Turkish president," German government spokesman Steffen Seibert told reporters.
He said Berlin was in "close consultation with partners who are affected by similar threats", while noting there had not been any "formal notification from the Turkish side".
If Erdogan expelled the diplomats, it would not be "in line" with the two countries' "close bilateral relationship" and their cooperation within NATO, Seibert said.
Erdogan decided Saturday to declare the ambassadors of 10 countries, including Germany and the United States, "persona non grata" for a joint statement backing the jailed Kavala.
The envoys' highly unusual joint declaration last week said the continued detention of the Parisian-born philanthropist and activist "cast a shadow" over Turkey's democracy and the judicial system.
The 64-year-old civil society leader and businessman has been detained without a conviction for four years.
Supporters view Kavala as a symbol of growing intolerance of political dissent by Erdogan since he survived a failed military putsch in 2016.
Expulsion orders are officially issued by foreign ministries and none of the Western capitals had reported receiving one by Monday.