Valentino Rossi says the coronavirus pandemic means he will have to take a decision on his future before the 2020 MotoGP season starts.

The Italian great will lose his factory Yamaha seat to Fabio Quartararo, who impressed during his rookie campaign last year, from 2021.

Yamaha offered to support Rossi should he want to continue, promising the "availability of a Factory-spec YZR-M1 bike" in a statement released in January.

Rossi had planned to delay a call on his future until the middle of this season, but with no racing having taken place yet due to the COVID-19 outbreak, he concedes he may have to take a call before returning to competitive racing.

"I am in a difficult situation, because like I said my first option is to try to continue because I have enough motivation and I want to continue," Rossi said in a Yamaha-organised social media interview.

"But it's very important to understand the level of competitiveness, because, especially in the second part of last year, we suffered very much and too many times I was too slow and I [could not fight for the] first five positions.

"So, in my mind, I have another year with the factory team and I need time to decide.

"And for me, I need like five/six races to understand with the new chief mechanic [David Munoz] and some modifications in the team if I can be stronger.

"The problem is [there is] no racing, so with the virus we have no racing. So, I think I will have to decide before racing because in the most optimistic situation we can race in the second half of the season.

"Around August or September, we hope, if everything is good. I have to make my decision before [then]. But anyway, I want to continue, but I have to do this decision without making any races.

"For sure, it's not the best way to stop because the situation is maybe we don't race in 2020 [at all].

"It's more fair to make another championship and maybe stop at the end of the next [year]. So, I hope to continue in 2021."