Charles Leclerc may be struggling under the pressure at Ferrari, a two-time Formula 1 world champion has declared.

Emerson Fittipaldi won titles in the early 70s for Lotus and McLaren, and he thinks Leclerc's own push to become world champion is making his teammate Carlos Sainz look better at the moment.

"I can see that Leclerc is under greater pressure than Sainz," he said. "And that pressure is coming from within. He wants to perform and deliver and they're not achieving.

"Carlos Sainz seems to be more consistent when it comes to finishing the races than Leclerc," the 76-year-old Brazilian added. "That will create more pressure on Charles.

"Knowing that his teammate is there, delivering results, that's the name of the game. When you have a teammate having the same kind of equipment, this starts creating pressure and if you're not mentally strong, it will make things difficult."

2016 world champion Nico Rosberg said at Monza last weekend that he thought Leclerc was "too kind" to Spaniard Sainz following their wheel-to-wheel battle for the podium.

"I mean, (he said) 'I had such a lovely fight, and what a great day, and I'm gonna have a beer with Carlos, we're going to have a laugh'. A bit strange," said the German.

Fittipaldi agrees that Leclerc might actually be losing his focus on his actual goal.

"Charles Leclerc needs to be more focused and not be so worried," he said.

"When a driver starts doing that, that's the worst he can do to himself. We know he has the talent, but he has to be more relaxed in my opinion. If he gets things easier, he'll perform better and make fewer mistakes," Fittipaldi added.

"Any athlete that puts too much pressure on themselves, you come out of a productive window. If you are overdoing it, it's not good and if you're underdoing it, you're not performing.

"Each athlete has a window of performance and to me, he's going over it and creating mistakes that don't do justice to his phenomenal talent," Fittipaldi added.

"Leclerc needs to put himself in that window. I know it's easier said than done." body check tags ::