Earlier, a spokesman for the German carmaker refused to comment on the speculation.
Earlier, a spokesman for the German carmaker refused to comment on the speculation, saying: "We confirm nothing, we deny nothing, we don't comment at all."
Germany's Sport Bild, however, said the test will take place on Wednesday and Thursday, and 30-year-old Glock commented: "I am very excited to test the (DTM) car, and also to meet up at Valencia with some familiar faces from my past at BMW."
Belatedly, BMW confirmed the news.
"We are pleased to be able to offer Timo Glock the opportunity to get to know our BMW M3 DTM in Valencia," said motor sport director Jens Marquardt.