The big question surrounding Valentino Rossi's MotoGP future is increasingly shifting from whether he will race on, to how long he will race on for.

When Yamaha announced that its most famous rider would not be part of their factory team in 2021, having signed rising star Fabio Quartararo instead, Rossi's racing future was hanging in the balance.

As The Doctor made clear, he would only continue if he was competitive - having been frustrated by tyre wear issues for most of last season - and would use the opening 6-7 races to decide if he should accept Yamaha's offer of factory support at a satellite (Petronas) team in 2021 or retire.

But the coronavirus has changed all that and Rossi now accepts he will need to decide his future before completing a racing lap this season. Everything points to the nine-time champion being back on the grid next year, not least because to bow out with a sparse season of 10-12 races (at best) would be a travesty.

As such, the question increasingly asked is how much longer will Rossi continue and whether the widely held concept of staying on for a 'farewell season' at Petronas is selling his intensions short.

Valentino's father and former grand prix winner Graziano Rossi feels his son can continue for up to four more years, which would put Valentino close to matching his race number of 46.

"In my opinion, he can still race for two, three or maybe even four years," Graziano told Rai Sport. "He certainly has no desire to stop today and probably not even in a year. Of this I am sure.

"I am convinced that Valentino is still a competitive rider and can win races if he has the right conditions.

"If, in this difficult situation [with the shortened calendar], experience will be needed, it could even be an opportunity for Valentino."

While the likes of Cal Crutchlow, Johann Zarco and Quartararo have come extremely close, no satellite Yamaha rider has yet won a MotoGP race.

That's not to say it won't happen, but the pressure on Rossi to deliver victories and beat the other Yamahas would certainly be reduced once out of the 'factory' garage. Might he thrive under such circumstances?

Petronas riders Quartararo and Franco Morbidelli finished fifth and tenth in last year's standings, with Rossi in seventh, while race-winning team-mate Maverick Vinales led the M1 challenge in third.