After the Hungaroring briefly masked the SF1000's problems at the last race, Vettel and Leclerc are braced for two difficult weekends at one of the most power-sensitive circuits on the calendar.
Ahead of the British and 70th Anniversary races at the track, a concerned Leclerc said: "I think we expect two quite difficult weekends on paper.
"I always try and like to be optimistic, so I'll have the same mindset going into the weekend, but realistically it's going to be pretty difficult."
Vettel agreed with the assessment of his team-mate, adding: "It's probably the right way to look at it. I think on paper it is not the track where we should be strongest with the current package that we have, but we are here to race.
"I always look forward to being on the grid and seeing what we can do. There are always decisions that need to be taken during the race with strategy and so on."
Two of the opening three weekends of the year have been affected by rain but the forecast for the British Grand Prix currently shows warm, dry weather across the entirety of the event.
That did not stop the four-time F1 champion from wishing for more rain.
"It doesn't look like rain for this weekend but maybe, you never know, we are in the UK," said Vettel, before jokingly adding: "It's probably where rain was born, but we'll see.
"Anything can come up so I guess we are the underdog, but maybe we can still have a good fight."
GPFans is a multi-platform, multi-language brand dedicated to Formula One coverage. We bring you all the ins and outs of the sport, 24/7, everything from up-to-the-minute news and features to the latest viral stories and clips.
We believe that a new generation of exciting, outspoken drivers will make F1 more popular than ever before, and we want to give our users access to as much of their heroes as possible, on and off the track. From Lewis Hamilton to Max Verstappen, Daniel Ricciardo to Sebastian Vettel, we provide in-depth analysis of every every Grand Prix in the season, from Australia to Abu Dhabi.
With Formula One under the new ownership of Liberty Media, how the sport is being covered is evolving, and GPFans will look to be at the heart of this progression into new media, as one of the fastest-growing sites covering the king of motorsports.