DTM and Formula E regular Frijns was due to contest the German endurance classic for the Car Collection Motorsport team, sharing the #3 Audi R8 LMS with Mirko Bortolotti, Christopher Haase and Markus Winkelhock.
However, ahead of Friday's third qualifying session, Audi released a brief statement saying that Frijns would take no further part in the weekend.
It added that the Dutchman was tested for COVID-19 and returned a negative result.
#15 Phoenix Racing Audi R8 LMS GT3: Kim-Luis Schramm, Michele Beretta, Jules Gounon, Frank Stippler
Audi Communications Motorsport