LISBON • McLaren are tightening procedures against Covid-19 to protect their Formula One drivers Carlos Sainz and Lando Norris, after what team principal Andreas Seidl called a "wake-up call" in Germany two weeks ago.

Reigning champions Mercedes had two positive cases at the Oct 11 Nurburgring race, and had to isolate team members and fly in replacements from England.

Racing Point billionaire owner Lawrence Stroll and his driver son Lance also tested positive that Sunday, with the Canadian becoming the second F1 driver after teammate Sergio Perez to be infected.

"What happened at the Nurburgring, that's just another wake-up call for the entire team to make sure we don't get complacent," Seidl said ahead of tomorrow's Portuguese Grand Prix.

"We did some additional measures for here again, in terms of separating the people even more as far as it is possible in the offices and in the garages.

"We did another step also with the drivers to separate them even more from the team during the race weekend, simply to make sure we do what is possible."

F1 is operating in a "bubble", with teams tested every five days and kept apart in the paddock.

They are also keeping replacement staff on standby and the governing body has tightened procedures since Nurburgring, with nobody allowed into the paddock without having produced a negative test result on site.

Mercedes team boss Toto Wolff also revealed that Lewis Hamilton and teammate Valtteri Bottas were isolating as much as possible.

"The drivers are the most restricted of the whole group, of the whole team," said the Austrian.

"It's certainly not a great situation for them because you almost need to live like a hermit."

In yesterday's first practice session, the Silver Arrows made it a one-two, with Bottas (1:18.410) edging Hamilton (1:18:749) as the first F1 session in Portugal since 1996 got under way.

REUTERS

F1 PORTUGUESE GRAND PRIX

Practice 3 (5.55pm) & qualifying (8.30pm) - Singtel TV Ch114 & StarHub Ch208