Red Bull must cope without sporting director Jonathan Wheatley for this weekend's Bahrain Grand Prix after he tested positive for COVID-19.
The 53-year-old Briton has not travelled to Bahrain and has begun a 10-day period in isolation.
Red Bull sit second in the constructors' championship this season, with Max Verstappen accounting for 170 of their 240 points and Alexander Albon contributing the rest.
Wheatley joined Red Bull from Renault in 2006 and has been a pivotal figure in the team's rise.
We can confirm that during mandatory pre-race testing in the UK, Sporting Director Jonathan Wheatley tested positive for COVID-19. In accordance with official protocols he will continue to isolate for the 10 day period and not attend the #BahrainGP pic.twitter.com/fvoeUOzJU3
— Aston Martin Red Bull Racing (@redbullracing) November 26, 2020
It remains to be seen whether he can return for next week's Ssakhir Grand Prix, which also takes place in Bahrain.
Red Bull said in a statement: "We can confirm that during mandatory pre-race testing in the UK, sporting director Jonathan Wheatley tested positive for COVID-19.
"In accordance with official protocols he will continue to isolate for the 10-day period and not attend the Bahrain GP.
"Jonathan's duties will be shared by a number of team personnel at this weekend's Bahrain GP.
"The positive test has not resulted in any other team members needing to isolate following contact tracing and will not affect the team's trackside operations."
