Quadruple world champion Alain Prost has defended Formula 1's teen rookie Lance Stroll.

Canadian Stroll's debut for Williams this year has been the subject of controversy, as his career has been bankrolled by his billionaire father.

Not just that, although the 18-year-old broke through for his maiden podium in Baku, he notably struggled during the first half of the season.

However, Prost thinks that much of the criticism was unfair.

"He was being criticised even before he started," he told Le Journal de Montreal.

"I said before the season that it would be difficult for him to manage his age and his inexperience. It's true that he has tested in the 2014 car, but he has had so much to learn, especially this year with these faster cars.

"But when you know F1, you know how difficult it is to get started. Look at Stoffel Vandoorne. He was considered one of the greatest hopefuls and he has had difficulties since the very beginning.

"But he's going to get better and better, and it's the same for Lance."

Prost, also an advisor for Renault's F1 programme, thinks that the biggest pressure on Stroll this year was the wealth of his father, billionaire fashion mogul Lawrence Stroll.

"It put extra pressure on him," Prost said. "And I think that's a pity, because without a minimum amount of talent, he would not be in F1.

"We have to give him time. Where we can judge is in his results by the end of the year and especially next year," he added. "His progress. Today, it is still too early."

Prost, 62, said that Stroll's podium performance in Baku was noteworthy.

"At the moment, he's not doing badly," said the Frenchman.

"Honestly, in Baku, I looked at his race and he was one of the only drivers not to make a mistake."

Stroll has picked up 18 points so far this season.