Having started comfortably inside the top 10 at Paul Ricard, Leclerc finished P16 and a lap down at the French Grand Prix after Ferrari simply could not get up to speed on Sunday.
While tyre difficulties affected drivers up and down the field after Pirelli increased the minimum tyre pressures following two failures in Azerbaijan, both Ferraris seemed to be hit the hardest with their struggles.
“Today it has been really difficult. Now it’s up to us to analyse well and to understand above all why we were so far [behind] in the race,” Leclerc told Sky Italia after the race.
“Both Carlos and I struggled a lot, with me we tried a last pit stop in the end to try restarting with the mediums, trying to do something different.
“With the settings on the wheel and the driving I tried everything but in the end we eat these tyres too fast and we have to understand why. For sure it’s a problem we have now, so we’ll keep pushing.”
With two more races to come in as many weeks, the Monegasque driver does not yet feel confident that they will be able to solve the issue any time soon.
He added: “In the short term, I don’t think so because in any case, as we saw, it’s quite a big problem, in particular here we have to say, but we struggled a lot.
“So I think it will take a bit of time, we’re still in time to do well next year but we have to really understand what’s slowing us down to understand for next year.”
Carlos Sainz fared slightly better than his Ferrari team-mate, but still dropped all the way out of the points after earning an encouraging P5 grid slot on Saturday.
He was also mystified about where the speed from his SF21 went on Sunday, after an impressive qualifying session.
“No, for sure no,” Sainz told Sky Italia when asked if Ferrari’s lack of pace was expected.
“We’re honestly really surprised, and really disappointed also.
“You never expect to be so slow and to have so much [tyre] degradation. It’s pretty clear today there was something that didn’t work with the tyres, and simply we don’t understand for now why we struggle so much in the race.
“[There were] cars that at the end of the race do 1:37, we did 1:39 when yesterday in qualifying we gave them half a second. So there’s a lot to understand about the tyre and I’m sure we’ll do our analysis and we’ll find some things for Austria.”
Additional reporting by Luca Brambilla