Nine-times world champion Valentino Rossi has tested positive for Covid-19 and will miss this weekend's Aragon MotoGP.
Rossi, who travelled back to his to his home in Tavullia, Italy after last weekend's French Grand Prix, confirmed on Thursday he woke up with slight fever and underwent two tests for Covid-19.
"The 'quick PCR test' result was negative, just like the test I underwent on Tuesday. But the second one, of which the result was sent to me this afternoon, was unfortunately positive," Rossi, 41, said on Twitter.
"I'm so disappointed that I will have to miss the race at Aragon."
The Italian becomes the first MotoGP rider to test positive for the coronavirus, although paddock members have previously tested positive for Covid-19.
Moto2 rider Jorge Martin was also forced to sit out of last month's Misano double-header after testing positive for the virus.
Yamaha confirmed Rossi followed all the health and safety protocols throughout the week and will now self-isolate, with his medical condition closely monitored by the team's medical staff.
Rossi, 13th in the championship standings with 58 points, said he is unlikely to return for the second round at Aragon on Oct. 25.
"I'd like to be optimistic and confident, but I expect the second round in Aragon to be a 'no go' for me as well," he said.
"I will now follow the medical advice, and I just hope I will be feeling well soon."
Rossi has failed to finish in each of the last three races, crashing out on the opening lap of last weekend's French Grand Prix.
Yamaha have made no mention of fielding a replacement for the upcoming races but this could open door for test rider Jorge Lorenzo, a three-times world champion, to make a return this season.