Fabio Quartararo "lost the most" at the French Grand Prix last weekend despite extending his lead in the riders' standings, according to Joan Mir.
Championship leader Quartararo was considered one of the favourites to win the race in his homeland but it was Danilo Petrucci who triumphed in the rain at Le Mans.
On the final lap the Petronas Yamaha rider took ninth from Mir, who slipped down to 11th when Maverick Vinales also got past him.
Quartararo consequently increased his advantage over Mir in the championship standings by two points to 10, though Andrea Dovizioso finishing fourth means just 19 points separate the top four riders in the title race.
Perhaps attempting mind games ahead of this weekend's Aragon Grand Prix, Mir expressed his opinion that Quartararo missed a great opportunity to gain far more significant ground on his rivals.
"I think the rider to beat this weekend is Quartararo," said Mir.
"He is the one who is the leader in the world championship and the one who may lose it. He is surely the one who lost the most at Le Mans.
"He had a good pace and could not do better and did not score [more] points compared to his rivals."
Quartararo was still proud of his performance given the conditions, though acknowledged they robbed him of a chance to back-to-back wins for the second time this season.
"Well for sure in the dry conditions we were there to fight for victory because our pace was great," Quartararo said.
"I think that we, let's say not lose, but I think the potential to finish on the podium was much higher [in the dry] than finishing on the podium in the wet by far.
"In rain I never felt that great on the bike, and at the end for me it was a tough race because the potential was better on the dry. But I'm still happy about my result in the rain.
"It was a good fight in the last lap, but for sure we had more potential on the dry to win much [more] points than we did."
After the Aragon Grand Prix there are just four more races remaining on the 2020 calendar.