It emerged early this week that she underwent a seat fitting at Sauber's Hinwil factory, and Speed Week now reports that she will make her test debut at the end of this month.
The report said de Silvestro will drive a few-year-old Ferrari at the Italian marque's Fiorano test track.
Another Sauber test driver, Russian teen Sergey Sirotkin, tested for the Swiss team in Bahrain earlier this week.
It is believed Sauber prioritised the test for Sirotkin so that he can obtain his mandatory super license and take part in Friday practice at Sochi later this year.
Linked with new Russian team backers, the 18-year-old managed the necessary 300 kilometres at a competitive pace.
"My shoes were too small," said Sirotkin, "and it was pretty painful when I was braking. When we changed the shoes, it was still not the best and difficult to drive.
"It was not easy," he added, "but I am glad we completed the 300kms."