At a time Sebastian Vettel finds himself being asked if he would benefit from the services of a sports psychologist, former teammate Daniel Ricciardo has said the German should be used to the pressure of fighting for the title.

A needless mistake on the opening lap in Italy was preceded by errors in Azerbaijan and Germany, and with six races remaining, Lewis Hamilton enjoys a 40-point lead over Vettel.

Speaking in Sochi, Ricciardo, who famously caught Vettel on the hop when he partnered him in 2014, his debut season with Red Bull, admitted he was surprised that the German appeared to be letting the pressure get to him.

"It's hard for me to really comment because though I have won races and I've dealt with some pressures, I've never dealt with the real pressure of fighting for a title and going head-to-head.

"Yes, I believe I would be able to cope with that pressure," he added, "but until I'm in that position I can't say 'yeah, he's not doing the right thing' or whatever. He has won titles before so maybe that's a little bit of the surprise, you think he's been here and should be used to it."

Asked if Ferrari might be part of the problem, Vettel having won all four of his titles with Red Bull, Ricciardo admitted: "Ferrari is maybe a different organization than Red Bull and there's different weights and pressures that come with Ferrari... again, I'm not sure, I'm speculating. But maybe these are things are adding more weight on the shoulders. We are all human.

"Lewis this weekend might crash in qualifying and then he has a terrible weekend. I don't know, things happen.

"Comparing like Seb and Lewis, for sure Lewis has been the kind of more solid guy, you know, more consistent this year. Seb's been able to produce some big races and performances but it has had more ups and downs."

Check out our Friday gallery from Sochi, here.