Race winner Sergio Perez drives during the Sakhir Grand Prix in Sakhir, Bahrain on Sunday. Photo: VCG

Lewis Hamilton is back in training and set to return for Mercedes at this weekend's season-ending Abu Dhabi Grand Prix, but only if he is passed fit and returns negative tests for COVID-19.

The seven-time world champion was absent from last week's action-filled Sakhir Grand Prix in Bahrain where his replacement and fellow Briton George Russell shone, despite a bungled Mercedes pit stop, on his way to ninth - his first points-­scoring finish.

Hamilton, 35, is expected to be given until Saturday morning at the very latest to prove his fitness, if needed, with the team continuing with Russell in his car.

Russell was nominated on Wednesday to be the Mercedes representative at a pre-event news conference at the Yas Marina Circuit on Thursday.

Nothing is certain, however, ahead of a race in which the champion team - for an unprecedented seven successive years - seek some redemption following their embarrassing tyre gaffes last Sunday.  

"We head into the final race looking for redemption after a disappointing race in Sakhir, where both George and Valtteri [Bottas] lost the opportunity to win," said team chief Toto Wolff.

"The pit stop problem has uncovered an underlying problem with our intercom and we've put measures in place, both technically and in the way we operate, to make sure it doesn't happen again."

The team's blunder happened when both drivers came in for new tires and were sent out on the wrong ones - with Bottas having to continue on a set he was prepared to discard. 

Russell had to pit again, but he was undone by a late puncture as he surged towards a possible maiden victory in thrilling fashion.

Russell's outstanding drive prompted many observers to claim he deserved another opportunity, but Wolff said the team are going to give Hamilton as long as he needs to make a comeback after missing a race for the first time in since his debut in 2007.

"There are still some question marks over who will be in the car this weekend in Abu Dhabi," said Wolff. 

"Lewis' condition is improving, but we won't know until closer to the time if he will be driving.

"We'll do everything we can to get him in the car and we know he's determined to be back as soon as possible, but his health is our main priority so we will see what the ­situation is and then make the call."

Hamilton has been in self-­isolation in Bahrain since his positive test and his 10-day period ends on Thursday. 

Earlier this week, he posted on social media that he felt "great" and had returned to training.

Mercedes added that Russell's nomination to appear for Mercedes in Thursday's news conference rota was not a ­signal that he is set to race again even though Williams, who released him last weekend, named reserve driver Jack Aitken in their equivalent slot.

To enter the United Arab Emirates this weekend, Hamilton is expected to require four negative tests and approval from government officials - and then join his team in their usual "bubbles" on Yas Island, which is in lockdown.