Nico Hulkenberg will drive for Racing Point in the Eifel Grand Prix after Lance Stroll was taken unwell, the team announced on Saturday.
"Lance did not feel 100 percent this morning and the team took the decision not to run him for the rest of the event," the team said on its website.
It was not made clear if Stroll had tested positive for Covid-19.
His team-mate Sergio Perez was quarantined for two weeks after returning from Mexico and testing positive for the coronavirus ahead of the British Grand Prix in July.
Stroll's seat will be taken by German driver Hulkenberg.
"Nico, who previously deputised for Sergio Perez at the Silverstone events, is familiar with the car and team already, and fortunately was in nearby Cologne," said Racing Point.
The Mercedes team were hit this week by two positive test results in their travelling race team, resulting in six staff going into isolation. Six replacements were flown to Germany on Thursday.