Valtteri Bottas finished fastest in practice for the Eifel Grand Prix as Racing Point's Lance Stroll was sidelined through illness.
While Bottas led Lewis Hamilton by 0.136 seconds at the Nurburgring, Stroll's participation for the remainder of the weekend is in doubt.
The Canadian driver's fitness will be reassessed by his Racing Point team ahead of qualifying later on Saturday.
But Nico Hulkenberg, who deputised for Stroll's team-mate Sergio Perez earlier this season after the Mexican contracted coronavirus, has arrived at the circuit and is on standby.
Racing Point tweeted: "Lance Stroll is not feeling 100 per cent this morning and will therefore not participate in FP3.
"His condition will be assessed after the session to evaluate whether he is fit to drive, at which point the team will confirm plans for qualifying."
On track, Bottas set the early pace in the opening action of the weekend after both Friday practice sessions were cancelled due to bad weather.
The persistent drizzle and fog which curtailed Friday's running were replaced by blue skies, complete with an air temperature of just eight degrees.
A number of drivers spun in the chilly conditions with Sebastian Vettel completing a pirouette at the final corner. George Russell and Nicholas Latifi also spun in their respective Williams cars.
Hamilton is bidding to equal Michael Schumacher's record of 91 victories on Sunday, but the world champion finished behind Bottas.
Bottas, who trails Hamilton by 44 points in the standings, will be looking to carry over his winning form from Russia after he took advantage of his team-mate's 10-second penalty to triumph for only a second time this year.
Charles Leclerc finished third for Ferrari, 0.456 secs down on Bottas, with Red Bull's Max Verstappen fourth and Vettel fifth. British driver Lando Norris was sixth for McLaren.
