Lewis Hamilton says he is trying to get in shape to return for the final Grand Prix of the season this weekend after contracting coronavirus.
The Mercedes driver missed last weekend's Sakhir Grand Prix after testing positive on 1 December.
He requires a negative test before he can leave isolation in Bahrain.
"It has been one of the hardest weeks I've had for some time," the world champion said in a video posted on social media.
"I've just been focusing on recovering and trying to get back in shape."
Hamilton said he woke up on Tuesday "feeling great and got my first work-out in [since his positive test].
"I wanted to let you know I'm OK. I hope I can get back in the car soon."
Hamilton did not say whether he had tested negative, which suggests that he has not at this stage.
If Hamilton does not recover in time, Briton George Russell will again stand in for him at Yas Marina, after losing out on a debut win for Mercedes on Sunday following a pit-stop mix-up and a puncture.
The latest Mercedes can put Hamilton in the car to enable him to race in Abu Dhabi is on Saturday.
If he tests negative in time, Hamilton still needs the approval of the United Arab Emirates authorities to travel to Abu Dhabi, as F1 personnel were allowed to travel between the two countries only on specific flights on Monday as part of a bubble system set up to limit the risks of spreading Covid-19.
Conversations are ongoing between Hamilton's management and the authorities on this matter.
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