Mark Webber says Sebastian Vettel's struggle to exert influence at Ferrari took its toll on the German driver's confidence and ultimately "wore him out".
Webber, who raced alongside Vettel at Red Bull Racing from 2009 to 2013, says his former teammate never succeeded in shaping the Scuderia and its Italian culture to his liking.
The Aussie believes that the shortfall, coupled with the rise at Maranello of Charles Leclerc progressively eroded Vettel's clout and confidence.
"All the opportunities are in Leclerc’s corner right now in terms of him being the next favourite one at Ferrari," said Webber, speaking to Mark Gallagher on the latter's 'At the Controls' podcast.
"Yes, Sebastian has done his best with what he could to set the team up and have it in a position to win a world championship in the last few years [but] it hasn’t happened.
"So I think his confidence has been very much rattled with the lack of penetration that he was able to have with the Italian culture. That’s a big thing.
"There’s a sort of Germanic way of going about things, borderline robotic as we know they are. The English, Aussies, Kiwis, South Africans are somewhere in the middle and then you’ve got the [Italians] at the other end.
"So that marriage I just think really wore him out. You can see he doesn’t look his age right now, I’ve told him that several times.
"But he’s had a good run at it, a hard run at it, but I think he’s just worn down. And maybe he knows more about the car than we do. But anyway, he might have a year off, who knows?
"I think he doesn’t feel he can get out of bed with a spring in his step driving for a red car right now and as obviously an athlete that’s a problem."
Although Mercedes has taken note of Vettel's availability for 2021, the 32-year-old's options for next season are limited, unless the four-time world champion is willing to race in F1's midfield.
But Webber very much doubts Vettel would be willing to take a step back, suggesting a year on the sidelines would perhaps work out better for him.
"I don’t know where he can go, I really don’t," commented the Aussie.
"Most of his career he’s been sniffing around podiums, apart from the first year at Toro Rosso, which he still won a race in that first year.
"I don’t see him at Renault at all. I see him letting it flush out off the back of ’21 and then maybe has a bit of a look at coming back.
"His age is super young to stop, but because he did start early, the trophy cabinet’s handy. I wouldn’t be surprised if he stops, but I really hope he doesn’t."
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