MotoGP title contender Maverick Vinales did not let the last-minute absence of his Covid-19 positive Yamaha teammate Valentino Rossi nor tricky wintry conditions cloud his performance as he topped Friday's Aragon Grand Prix opening free practice timesheets from championship leader Fabio Quartararo.
Vinales is the lone Yamaha factory bike rider at this weekend's 10th leg of the MotoGP season in Spain after seven-time champion Rossi tested positive on the eve of practice after developing a mild fever.
Vinales is placed fourth in the closest championship title race run-in for years, only 19 points off Quartararo.
The young Frenchman with Yamaha's satellite SRT team was one of several riders who crashed as the chilly weather caused problems with tyre temperatures making life difficult for not only Quartararo but also Johann Zarco, Marc Marquez's brother Alex Marquez, Iker Lecuona and Franco Morbidelli. All escaped injury.
Quartararo however ended the day with a smile on his face after filling second to Vinales, his SRT teammate Morbidelli third for a Yamaha-engined first day practice 'podium'.
"That was a positive opening day, I fell this morning but that's fine. Our pace is goood but we have a lot to improve on tomorrow (in further practuce and qualifying)," the winner of the opening two rounds of the championship said.
Vinales was the only rider to drop below 1min 48sec, his lap of 1min 47.771sec achieved in the warmer afteroon placing him 0.249s ahead of Quartararo at the start of what his Yamaha team director Massimo Meregalli described as " a very strange weekend" for the team coping with Rossi joining Cristiano Ronaldo and other global sports stars in being touched by the pandemic.
"We had the bad news yesterday that Valentino is not able to join us here this weekend. It's a situation that none of us ever even wanted to imagine, and he is dearly missed by the whole team."
On their track showing, Vinales reported that even in far from ideal conditions "our lap times are pretty fast, the bike is working well from the first laps".
He added: "We know this track is good for us, because it has a lot of flowing corners. We just needed to improve in a few corners and we did that today, which makes me very happy. Today it was also windy here, and usually the Yamaha is very stable even then."
With 'The Doctor' Rossi unable to line up on Sunday and in the continued absence of fractured arm victim Marc Marquez it means this weekend's grid is deprived of two men who between them have won 13 of the past 19 world championships.
Quartararo is in pole to be crowned his successor - he leads Joan Mir by 10 points with Andrea Dovizioso and Vinales only a further eight and nine points adrift.
Despite being second in the standings Mir has yet to win a MotoGP race, although the Spaniard has tasted victory on this circuit while racing Moto3 in 2017.
"It's a track that I like a lot and I'm coming to it in good shape," said Mir who finished 11th in the rain at Le Mans last weekend.
"I'm still close to the lead in the championship standings and I managed to rescue some points in the last race."
The long straights could be a problem for Mir too and that could leave the door open for Dovizioso, three-time runner-up to Marquez in the championship.
The 34-year-old Italian is being dropped by Ducati at the end of the season. The prospect of leaving as reigning world champion could add to his motivation.
Meanwhile Rossi was not the only rider forced to miss this weekend due to Covid-19.
In Moto3 young Italian Tony Arbolino must quarantine after coming into contact with a fellow passenger to Spain who tested positive for the virus.