Dr Helmut Marko has backed Ferrari's Charles Leclerc to hit back at his on-form teammate Carlos Sainz.

Sainz, a former protege of Red Bull and Marko, has edged ahead of Leclerc's performance since the summer break - culminating in back-to-back poles and a breakthrough second career victory in Singapore last week.

"He is currently in top form and was already extremely fast in Monza," Marko told Kleine Zeitung newspaper when asked about Sainz's form.

"But Leclerc had to slow down in the race. I don't think he (Leclerc) will be demoted at Ferrari."

For his part, Sainz explained that there has been no "secret" to his recent form. "Just work and a greater understanding of the car.

"I believe I have understood the direction to take to exploit a little more potential from the car," he added.

Leclerc admits that Sainz has been "very, very strong" in recent weeks.

"It is great to have him in this form, because it also pushes me to understand my driving style a little more and to try to adapt it to this car," said the Monegasque driver.

Max Verstappen's father Jos said this weekend that the "top drivers" in Formula 1 always prefer a very strong front end, tending towards oversteer.

The current Ferrari, on the other hand, is faster when it's set up to understeer.

"I don't feel completely comfortable at the moment," Leclerc admitted at Suzuka. "There's too much understeer for my taste and I'm having a hard time dealing with it.

"Because of the unpredictability of the car, I can't get the oversteer I want. But first and foremost it's fantastic to see that at least the competitiveness is there.

"This car was a challenge from the start, because we need to play it safe in terms of balance. We can't run with a lot of grip at the front.

"It's not that it's a car with understeer, but you have to force it to be predictable with the setup," he explained.