Days after Juan Pablo Montoya suggested that much of Sebastian Vettel's problem is with his car, rather than his mental approach, the German has admitted that he lacks "absolute trust" in the SF90.

"I think he doesn't like something in the car or this year's tyres and Leclerc is able to better adapt," the Colombian told Motorsport.com. "He has to suffer to go as quick as the other guy, and because he has to suffer and he is not comfortable, he makes mistakes.

"When you're not happy with the car and you push, mistakes happen," he added. "I don't think it's a mental thing. It is more a technical one. It's about understanding, having someone on your side who is able to find what's going on."

Speaking at the start of the Singapore weekend, less than two weeks after his unforced spin in Ferrari's home race at Monza, Vettel appeared to agree with Montoya's claim.

"I don't think it's mental," he told reporters. "It's not that I'm in the wrong place, I think I'm doing the right things, so that's why I think it's crucial not to complicate things too much.

"Here and there I might not have the absolute trust in the car and the best feeling yet," he continued, "but I think it's improving, my understanding of the car, and then it's a question of lining up the details.

"I'm sure that things will click and start to fall into place," he added, "so we need to keep our heads down. There's always things we can do better and that I can do better and work on, so we will see how the next races go."

The German's mistakes, coupled with back-to-back wins for teammate Charles Leclerc, have seen the four-time champion under increasing pressure from the media, which, if he is suffering a confidence issue, will only add to the pressure.

When it was pointed out that in the last seven race weekends, other than the back-to-back wins, Leclerc has out-performed him in qualifying also, Vettel replied: "I think first you need to be fair and say that he is very quick.

"However, I think we are judging qualifying where I didn't have the best run," he continued. "A couple of qualifying sessions where I didn't take part in Austria and Germany, then Monza only half. But I don't think there is anything particular standing out.

"I think one is just to be fair and admit that if he out-qualifies me then he is doing a better job, but then you need to look at the reasons why."

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