Lewis Hamilton is "devastated" that he will miss this weekend's Sakhir Grand Prix after testing positive for coronavirus.
Seven-time Formula One champion Hamilton awoke with mild symptoms on Monday and returned a positive test for COVID-19.
According to Mercedes, he found out on the same day that a close contact prior to his arrival in Bahrain for last weekend's race had also tested positive.
The team also said Hamilton tested negative three times prior to the Bahrain Grand Prix.
Hamilton is expected to be replaced by Stoffel Vandoorne or Esteban Gutierrez for the second race at Bahrain International Circuit.
In a statement posted on social media, Hamilton wrote: "I'm devastated that I won't be racing this weekend. Since we started the season in June, my team and I have been taking all the precautions we possible can and following the regulations everywhere we've been in order to stay safe.
"Unfortunately, even though I returned three negative results this past week, I woke up yesterday morning with mild symptoms and requested another test which came back positive. I've immediately gone into self-isolation for 10 days.
"I'm gutted not to be able to race this weekend but my priority is to follow the protocols and advice to protect others. I'm really lucky that I feel ok with only mild symptoms and will do my best to stay fit and healthy.
"Please look after yourselves out there, you can never be too careful. These are worrying times for everyone and we need to make sure we are looking after ourselves and each other. Stay positive."
Hamilton wrapped up the title in Turkey last month and triumphed in Sunday's first race in Bahrain.