Since returning from the appendix surgery that ruled him out of the Saudi Arabian Grand Prix, Sainz has outqualified Leclerc in both Australia and Japan, and won the Melbourne race from second on the grid.
Leclerc has also finished behind his team-mate in both races, placing as runner-up at the Australian Grand Prix and finishing fourth behind the podium-finishing Sainz at Suzuka.
Asked if it was the case that Sainz had adapted to Ferrari's 2024 machinery more quickly within the opening races, Leclerc stated that his team-mate had simply been performing at a higher level in the most recent two races.
"I think it's as simple as he's doing a better job. I think in Bahrain, it's difficult to compare because on my side I was facing issues and I think it was a very strong weekend apart from that," Leclerc explained.
"However, in the last two races, he's just been stronger. It's up to me now to work, especially in the qualifying pace, which is normally a strength.
"I've been struggling to put the lap together; it's a very fine line to get it right or completely wrong on the out lap and putting the tyres in the right window.
"For now, I have been struggling more than what Carlos has done and he's driving at a very high level. I have been working a lot on that. And normally when I work on points, I'm quite confident on improving pretty quickly.
"I'm not worried, but obviously now I need to show that on track - starting from tomorrow in qualifying."
Looking ahead to the weekend and the demands of the Shanghai circuit, Leclerc expected Ferrari to be closer to Red Bull than it had been at Suzuka, the fast and technical Japanese circuit having played to the RB20's strengths.
The potential for front-tyre graining and greater prevalence of lower-speed corners appear to suit the sensibilities of Ferrari's SF-24, and Leclerc says the focus is on extracting that immediately in the context of a sprint weekend.
"On paper, I think it's a track where we could be a bit stronger compared to Suzuka, but we'll just approach it the same way; I still think that Red Bull will have the upper hand this weekend," the Monegasque added.
"We'll just have to focus on ourselves because it can be very easy [to make mistakes] as we've seen especially in qualifying in Suzuka - I didn't do a good job the Saturday and then you don't go from fourth to fifth, but you go from fourth to eighth.
"I think in the race we will be [closer]. But let's see, it's been a very long time since we last drove here. I saw the track was painted, or there was something strange on it, so also this we will have to see how our car behaves on that, and what are the main limitations in the race.
"But on paper, I think we shall be closer to them."
