A mathematical chance to be champion still exists, but only if Mir suffers a non-score and Vinales would still need to claim 45 out of the remaining 50 points.
To put that into perspective, Vinales has scored a total of 38 points in the five races since his Misano victory.
“Yes, I mean, Mir has to make a mistake, and we need to win one race and be second in the other,” Vinales said. “So for sure it’s very difficult, honestly, I never think about it.
“Our problem is not the championship, it’s totally other things. Right now we are very far on the speed, and that’s what we need to recover.”
Having dropped 19 points behind Mir after Aragon, Vinales had needed a strong result at Valencia to get his title challenge back on track.
Hopes were high after being quickest of all in the last year’s post-season test with the 2020 Monster Yamaha and revied Michelin rear tyres.
But by the end of Friday practice Vinales had been given a pitlane start for using an extra engine, a legacy of the Jerez failure and resulting valve controversy, and also lost some of his crew after a positive Covid test.
Vinales went on to climb from 21st to 13th in the race, but all his gains were due to mistakes from riders ahead.
The Spaniard was 25.403s behind Mir at the finish, having lost 13.355s on the opening lap.
Subtracting the pit lane start from Vinales’ race time leaves a deficit of +12.048s, which would still only equate to tenth place on Sunday.
While this season’s chances look to be over, Vinales says he knows little about Yamaha’s 2021 developments.
“We don’t have any new parts to try during the last two races, so I don’t know really what is going to happen,” Vinales said. “We don’t have any more information than the bike we have right now.
“Honestly, for sure Yamaha understand. They know that we have problems, they know we are in trouble, and for sure they will try to work.
“Hopefully next year there are four or five tracks where the bike is fantastic, and we can try to win the races,” he added, echoing Fabio Quartararo‘s comments that when the M1 works well at circuit straight away, they can fight for victory. But if not, they never recover.
Petronas rider Quartararo starts the final two rounds tied for second in the standings with Suzuki’s Alex Rins and is just four points ahead of 2021 Factory Yamaha team-mate Vinales.