George Russell was listed for the champions in a Thursday news conference schedule, after impressing as a stand-in last weekend in Bahrain, but Mercedes said they could leave a decision open until Saturday.
Reviewing the pandemic-hit season in a video conference with reporters from Yas Marina, Renault’s Ricciardo was asked what had been the weirdest or craziest thing to happen to him.
“I did wake up one morning with like a false-negative or a false-positive, whatever they call it. So I had a scare at like 6am one morning,” he said.
“There was a bit of panic and that wasn’t fun. I was fine in the end, but that obviously was something I hadn’t gone kind of through before and then you start playing games in your head like ‘do I feel a little…’ and ‘maybe I do have it…”
Ricciardo’s team clarified that it was an inconclusive test, which the Australian said occurred after Italian races and before the Russian GP in late September.
Formula 1 has operated ‘bubbles within bubbles’ since the season started in July after the scheduled March opener in Australia was cancelled when a McLaren team employee tested positive.
Mexican Sergio Perez and Canadian Lance Stroll, Racing Point teammates, tested positive earlier in the year. Hamilton’s result came after he won his record-equalling seventh championship in Turkey last month.
Ricciardo, who is joining McLaren at the end of the season after two years with Renault, said he had become more disciplined about isolating after Perez’s positive test.