Felipe Massa has praised Max Verstappen for becoming a more "mature" driver in recent seasons, declaring that the Dutchman is now "ready to win".
Verstappen made his F1 debut with Toro Rosso back in 2015, at the age of 17, after just one year in single-seater racing.
While he displayed impressive pace from the outset, several rivals raised questions over his approach to racing, with a so-called 'Verstappen rule' being introduced at one stage to prevent moving under braking.
"I think maybe in his first two, three years, he was very inconsistent," said Massa on the F1 Nation podcast.
"He was really, really quick all the time, doing amazing races, but also doing some stupid mistakes, like closing the car on braking points, stupid things that were just causing him this impression that he's not mature."
"He started to respect the rules"
Massa reckons the turning point for Verstappen came in 2018, when he recovered from a difficult run of races to rack up consistent podium finishes.
"Maybe after the second part of the season, in his last year with Daniel [Ricciardo] in Red Bull, he just changed a little bit his maturity," Massa added.
"He started to make a lot less mistakes, he started to respect a lot more the rules.
"Even the year after, when he didn't have really a big competition in terms of a teammate, inside the team, I think he grew up massively.
"Today, I think he's really mature, quick, doing an amazing job, also no mistakes - so he's ready to win."
Verstappen leads Lewis Hamilton by eight points in the championship standings ahead of the final two races of the season.
F1 Podcast: Is it game over for Red Bull after Hamilton's Qatar domination?
Does Lewis Hamilton's recent run of form against Max Verstappen now make him the favourite to claim the title? F1 journalists Dieter Rencken, Thomas Maher and Mike Seymour discuss this and more in the latest episode of the RacingNews365 podcast!